Building the heap: racking 30 petabytes of hard drives for pretraining | Hacker News Reader

Building the heap: racking 30 petabytes of hard drives for pretraining

si.inc

412 pointsnee1r274 comments

The linked Discord post is also interesting and fun to read. Most of the post is more serious but this is one of the small gems:

> One thing we discovered very quickly was that [world cup] goals scored showed up in our monitoring graphs. This was very cool because not only is it neat to see real-world events show up in your systems, but this gave our team an excuse to watch soccer during meetings. We weren’t “watching soccer during meetings”, we were “proactively monitoring our systems’ performance.”

https://discord.com/blog/how-discord-stores-trillions-of-mes...

It is linked as evidence for Discord using "less than a petabyte" of storage for messages. My best guess is that they multiplied node size and count from this post, which comes out to 708 TB for the old cluster and 648 in the new setup (presumably it also has some space to grow)

yeah we weren't sure about putting that number esp whether it includes all the image attachments, but in any case it's at least around the right reference class for the largest text data operations.

Nice writeup. All of the technical detail is great!

I'm curious about the process of getting colo space. Did you use a broker? Did you negotiate, and if so, how large was the difference in price between what you initially were quoted and what you ended up paying?

We reached out to almost every colocation space in SF/some in Fremont to get quotes. There wasn't a difference between the quote price and what we ended up paying, though we did negotiate terms + one-time costs.

Please consider posting the quotes, even if you have to redact colo names.

Fun piece, thanks to the author. But for vicarious thrills like this, more pictures are always appreciated!

If the authors chime in, I'd like to ask what "Standard Intelligence PBC" does.

Is it a public benefit corp?

What are y'all building?

We did want more pictures!! Recently bought a Sony A7III to capture more fun moments like this.

We're working on pretraining computer action models from the ground up—hence the pretraining data cluster. We're a public benefit corp because we think its important for AGI to built in the public's interest + are planning on automating a lot of the work done on computers!

"The best camera is the one you have with you." Looking forward to the next buildout post!

Many colos disallow photography.

You could get pretty close to the cost 1$/TB/month using Hetzner's sx135 with 8x22TB so 140TB in raidz1 for 240 eur. Maybe you get a better rate if you rent 200 of them. Someone else takes care of a lot of risks and you can sleep well at night

I don't think Hetzner provides locations in SF. Those 100GBit connections don't do much if they need to connect outside the city the rest of the equipment is in, but maybe peering has gotten better and my views are outdated.

You're good. The speed of light through a glass fiber is still just as slow as it ever was.

yeah it's totally plausible that we go with something like this in the future. We have similar offers where we could separate out either the financing, the build-out, or both and just do the software.

(for Hetzner in particular it was a massive pain when we were trying to get CPU quotas with them for other data operations, and we prob don't want to have it in Europe, but it's been pretty easy to negotiate good quotes on similar deals locally now that we've shown we can do it ourselves)

You cannot use hetzner for anything serious.

They'd most likely claim abuse and delete your data wholesale without notice

100% this. Hetzner has no problems completely blowing away whatever you've got running for arbitrary reasons. And their support is incresibly bad.

Your math does not math. It is more like $2/TB/month with minimal redundancy.

It's quite cheap to just store data at rest, but I'm pretty confused by the training and networking set up here. It sounds like from other comments that you're not going to put the GPUs in the same location, so you'll be doing all training over X 100 Gbps lines between sites? Aren't you going to end up totally bottlenecked during pretraining here?

yeah we just have the 100gig link, atm that's about all the gpu clusters can pull but we'll prob expand bandwidth and storage as we scale.

I guess worth noting that we do have a bunch of 4090s in the colo and it's been super helpful for e.g. calculating embeddings and such for data splits.

How did you arrive at the decision of not putting the GPU machines in the colo? Were the power costs going to be too high? Or do you just expect to need more physical access to the GPU machines vs the storage ones?

When I was working at sfcompute prior to this we saw multiple datacenters literally catch on fire bc the industry was not experienced with the power density of h100s. Our training chips just aren't a standard package in the way JBODs are.

Isn't the easy option to spread the computers out, i.e. not fill the rack, but only half of it?

A GPU cluster next to my servers has done this, presumably they couldn't have 64A in one rack so they've got 32A in two. (230V 3phase.)

Rackspace is typically at a premium at most data centers.

I'm more surprised that a data centre will apparently provide more power to a rack than is safe to use.

My info may be dated, but power density has gone up a ton over time. I'd expect a lot of datacenters to have plenty of space, but not much power. You can only retrofit so much additional power distribution and cooling into a building designed for much less power density.

This is my experience as well. We have 42u racks with 8 machines in them because we cant get more power circuits to the rack.

yep this was the case for us.

Adding the compute story would be interesting as a follow up.

Where is that done? How many GPUs do you need to crunching all that data. Etc.

Very interesting and refreshing read though. Feels like what Silicon Valley is more about than just the usual: tf apply then smile and dial.

30PB / 100Gbps comes down to about a month, 4 links would give you a week, so that seems pretty quite acceptable for a training run, especially since you can overlap the initial loading of the array with the first training, i.e train as data becomes available.

It goes without saying any data pre-processing needs to be done before writing, at the storage site, or on the training GPUs.

For a workload of that size you would be able to negotiate private pricing with AWS or any cloud provider, not just CloudFlare. You can get a private pricing deal on S3 with as little as half a PB. Not saying that your overall expenses would be cheaper w/a CSP than DIY, but its not exactly an apples to apples comparison of taking full retail prices for the CSPs against eBayed equipment and free labor (minus the cost of the pizza).

egress costs are the crux for AWS and they didn't budge when we tried to negotiate that we them, it's just entirely unusable for AI training otherwise. I think the cloudflare private quote is pretty representative of the cheaper end of managed object-bucket storage.

obv as we took on this project the delta between our cluster and the next-best option got smaller, in part bc the ability to host it ourselves gives us negotiating leverage, but managed bucket products are fundamentally overspecced for simple pretraining dumps. glacier does a nice job fitting the needs of archival storage for a good cost, but there's nothing similar for ML needs atm.

What sort of deal are you taking about? Would it be 50% or more?

You can get way higher than 50% discounts with AWS (or any cloud) depending upon the scale of the buy.

Not for that minimum 0.5PB volume.

Even at 10PB, the storage commit discounts won't be anywhere near 50%. Probably more like 10-20%, if that.

That's basically scaled up story of 'I store my files on my computer and it is 10x cheaper than using dropbox'

While disks fail rate is already explored in another threads here, there is one related thing that catch my interest. Disk failure in such setup is not just cost of new disk + replacement cost (someone has to go there and change it!). It also inconvenience with dealing with failing requests. Ok, you are willing to lose 5% of your dataset. But are your '200-lines of code' robust enough to handle such cases. What if disk didn't fail, but start to be veeeeery slow. Does your training process can efficiently skip such bad objects. Do you have enough transparency to understand how much data you already lost? Is it still below 5%? And so on and so forth.

I feel like this article was written right after they built this construction and before let say 6 months of usage. Because I'm pretty sure their costs will go much higher than they calculated here. Especially if they start including hidden costs, like the work needed to be done on training side.

Yes, cost for self-hosting most probably still be less than aws (aws is not cheap). But it might start to be comparable with storage solutions of small ('neo') cloud providers if you buy gpu there.

Had the pleasure of helping rack drives! Nothing more fun than an insane amount of data :P

Thanks for helping!!!

No mention of disk failure rates? curious how it's holding up after a few months

good point

The disk failure rates are very low when compared to decade ago. I used to change more than a dozen disks every week a decade ago. Now it's an eyebrow raising event which I seldom see.

I think following Backblaze's hard disk stats is enough at this point.

Backblaze reports an annual failure rate of 1.36% [0]. Since their cluster uses 2,400 drives, they would likely see ~32 failures a year (extra ~$4,000 annual capex, almost negligible).

[0] https://www.backblaze.com/cloud-storage/resources/hard-drive...

Their rate will probably be higher since they are utilizing used drives. From the spec:

2,400 drives. Mostly 12TB used enterprise drives (3/4 SATA, 1/4 SAS). The JBOD DS4246s work for either.

Not necessarily, since disk failures are typically U-shaped.

Buying used drives eliminates the high rate of early failure (but does get you a bit closer to the 2nd part of the U-curve).

Typically most drives would become more obsolete before hitting the high failure rate of the right side of the U-curve from longevity (7+ years)

I bet you still have a higher early failure rate because of the stress from transportation, even if there's no funny business. And I expect some funny business because used enterprise drives often come with wiped SMART data, some drives may have been retired by sophisticated clients who decided they were near failure.

Physically moving the drive tends to reset the U-shape. Some will be damaged.

They mentioned the cluster being used enterprise drives, I can see the desire to save money but agree, that is going to be one expensive mistake down the road.

I should also note personally for home cluster use, I learned quickly that used drives didn’t seem to make sense. Too much performance variability.

in a datacenter context failure rates are just a remote-hands recurring cost so it's not too bad with front-loaders

e.g. have someone show up to the datacenter with a grocery list of slot indices and a cart of fresh drives every few months.

Used drives make sense if maintaining your home server is a hobby. It's fun to diagnose and solve problem in home servers, and failing drives give me a reason to work on the server. (I'm only half-joking, it's kind of fun)

If I remember correctly, most drives either:

1. Fail in the first X amount of time

2. Fail towards the end of their rated lifespan

So buying used drives doesn't seem like the worst idea to me. You've already filtered out the drivers that would fail early.

Disclaimer: I have no idea what I'm talking about

we don't have perfect metrics here but this seems to match our experience; a lot of failures happened shortly after install before the bulk of the data download onto the heap, so actual data loss is lower than hardware failure rates

Where did you source them? I've thought about buying HDDs from a vendor like serverpartdeals.com but was unsure how reliable the drives would be.

Over in hardware-land we call this "the bathtub curve".

I've mentioned this story before, but we had massive drive failures when bringing up multiple disk arrays. We get them racked on a friday afternoon, and then I wrote a quick and dirty shell script to read/write data back and forth between them over the weekend that was to kick in after they finished striping the raid arrays. By quick and dirty I mean there was no logging, and just a bunch of commands saved as .sh. Came in on Monday to find massive failures in all of the arrays, but no insight into when they failed during the stripe or during stressing them. It was close to 50% failure rate. Turned out to be a bad batch from the factory. Multiple customers of our vendor were complaining. All the drives were replaced by the manufacturer. It just delayed the storage being available to production. After that, not one of them failed in the next 12 months before I left for another job.

> next 12 months before I left for another job

Heh, that's a clever solution to the problem of managing storage through the full 10 year disk lifecycle.

I wonder if they'll go with "toploaders" - like Backblaze Storage Pods - later. They have better density and faster setup, as they don't have to screw in every drive.

They got used drives. I wonder if they did any testing? I've gotten used drives that were DOA, which showed up in tests - SMART tests, short and long, then writing pseudorandom data to verify capacity.

yeah we're very interested in trying toploaders, we'll do a test rack next time we expand and switch to that if it goes well.

w.r.t. testing the main thing we did was try to buy a bit from each supplier a month or two ahead of time, so by the time we were doing the full build that rack was a known variable. We did find one drive lot which was super sketchy and just didn't include it in the bulk orders later. diversity in suppliers helps a lot with tail risk

"don't have to screw in every drive" is relative, but at least tool-less drive carriers are a thing now.

A lot of older toploaders from vendors like Dell are not tool-free. If you bought vendor drives and one fails, you RMA it and move on. However if you want to replace failed drives in the field, or want to go it alone from the start with refurbished drives... you'll be doing a lot of screwing. They're quite fragile and the plastic snaps easily. It's pretty tedious work.

Used Supermicro machines of this generation and very cheap (all things considered)

https://www.theserverstore.com/supermicro-superstorage-ssg-6...

>We threw a hard drive stacking party in downtown SF and got our friends to come, offering food and custom-engraved hard drives to all who helped. The hard drive stacking started at 6am and continued for 36 hours (with a break to sleep), and by the end of that time we had 30 PB of functioning hardware racked and wired up.

So how many actual man hours for 2400 drives?

around 250

Well done! I love the honest write up and the “can do” attitude. Must have been a lot of fun too. Out of interest why do you think you made the mistake of buying 20x more drives than you needed instead of the denser storage that you mention? Was there a reason you opted for this?

He did mention that it would have been a higher up-front cost.

I think <2x more drives than needed, not 20x (24 vs 14TB), but the racks holding the drives could've been denser. Around the same cost in any case and our colo doesn't charge for space, so it's not a big deal and we were just going with what we were familiar with, but something to try.

Oops sorry, my bad! Great to read all about it - good luck with the project.

I love this story. This is true hacking and startup cost awareness.

Thanks!! :)

So how do they get this data to the GPUs now...? Just run it over the public internet to the datacenter?

They can rent a dark fiber for themselves for that distance, and it'll be cheap.

However, as they noted they use 100gbps capacity from their ISP.

We want to get darkfiber from the datacenter to the office. I love 100Gbps

I'm now envisioning a poster with a strand of fiber wearing aviators with large font size Impact font reading Dark Fiber with literal laser beams coming out of the eyes.

Does San Francisco really still have dark fiber? That 90s bubble sure did overshoot demand.

DWDM tech improvements have outpaced nearly every other form of technology growth, so the same single pair of fiber that used to carry 10 Mbps can now carry 20 Tbps, which is a 2,000,000x multiplier. The same somewhat-fixed supply of fiber can go a very long way today, so the price pressure for access is less than you might expect.

I think these days folks say "dark fiber" for any kind of connection you buy. It bothers me too.

I meant a “single mode, non terminated fiber optic cable from point to point”. In other words, your own cable without any other traffic on it.

A shared one will be metro Ethernet in my parlance.

Noob question, is there an in-between where people sell spectrum bands on a shared fiber without going up to L2? Or is that just too complex compared to using off the shelf ethernet and sharing that.

Yep, absolutely, often called "wave/wavelength" or "lambda" service, or "lit fiber".

7.5k for zayo 100gig so that's like half of the MRC

yeah, exactly! we have a 100G uplink, and then we use nginx secure links that we then just curl from the machines using HTTP. (funnily HTTPS adds overhead so we just pre-sign URLs)

But where do you get 90 million hours worth of video data?

And not just any video data, they specifically mentioned screen recordings for agentic computer uses. A very specific kind of video. My guess is they have a partnership with someone like Rewind.ai

“For your privacy, your screen and audio recordings are stored locally and NEVER leave your Mac.”

Tell me it’s only someone _like_ Rewind and not actually them! Quoting from the Privacy page they link in their header.

> we prob don't want to have it in Europe

Best indicator as to what that is.

Arrr matey

Assuming my calculation is accurate, 90,000,000 hours of video using around 30 PB comes to an average bit rate of about 760k. (Hard to guess though bc I doubt they’re using up all the space they provision day1)

So my guess is either CCTV type of footage where there’s large gaps of motion / high GOP / big codec gains - or something like desktop recordings which are generally very low bit rate even though they can be high res. At that bitrate I can’t imagine it’s something like YouTube video. (Unrelated to the bitrate maybe it’s something like all older public domain videos). I would love to have an idea of what type of videos they are using (just out of curiosity)

Shows how crazy cheap on prem can be. tips hat

tips hat back

Not included is overhead of dealing with maintenance. S3/R2 generally don’t require OPS type dedicated to care and feeding. This type of setup will likely require someone to spend 5 hours a week dealing with it.

I once had about three racks full of servers under my control, admittedly they weren't a ton of disks, but still the hardware maintenance effort was pretty much negligible over a few years (until it all went to the cloud).

The majority of server wrangling work I spent dealing with OS updates and, most annoyingly, OpenStack. But that's something you can't escape even if you run your stuff in the cloud...

With S3/R2 whatever, you do get away from it. You dump a bunch of files on them and then retrieve them. OS Updates, Disk Failures, OpenStack, additional hardware? Pssh, that's S3 company problem, not yours.

$LastJob we ran a ton of Azure Web App Containers, alot of OS work no longer existed so it's possible with Cloud to remove alot of OS toil.

True, this is a large reason why we chose to have the datacenter a couple blocks away from the office.

Why 5h a week? Just for hardware?

5h a week is basically 3 days a month. So if you have an issue that takes a couple of days per month to fix, which seems very fair, you're at that point.

a) 5hrs/week is negligible compared to that potential AWS bill.

b) The seem tolerant of failures so it's not going to be anything like 5hrs/week of physical maintenance. It will be bursty though (eg. box died, time to replace it...) but assuming they have spares of everything sitting around / already racked it shouldn't be a big deal.

And this is actually relatively expensive.

My question isn't why do it yourself. A quick back of the envelope math shows AWS being much more expensive. My question is why San Francisco? It's one of the most expensive real estate markets in the US (#2 residential, #1 commercial), and electricity is expensive. $0.71/KwH peak residential rate! A jaunt down 280 to San Jose's gonna be cheaper, at the expense of. having to take that drive to get hands on. But I'm sure you can find someone who's capable of running a DC that lives in San Jose and needs a job so the SF team doesn't have to commute down to South Bay. Now obviously there's something to be said for having the rack in the office, I know of at least two (three, now) in San Francisco, it just seems like a weird decision if you're already worrying about money to the point of not using AWS.

Article says their recurring cost is $17.5k, they'll spend at least that amount in terms of human time tending to their cluster if they have to drive to it. It's also a question of magnitudes, going from $0.5m/mo to $0.05m/mo (hard costs plus the extra headaches of dealing with cluster) is an order of magnitude, even if you could cut another order of magnitude it wouldn't be as impactful.

Problem when you self-roll this is that you inevitably make mistakes and the cycle time of going down and up ruins everything. Access trumps everything.

You can get a DC guy but then he doesn't have much to do post setup and if you contract that you're paying mondo dollars anyway to get it right and it's a market for lemons (lots of bullshitters out there who don't know anything).

Learned this lesson painfully.

it's not just in sf it's across the street from our office

this has been incredibly nice for our first hardware project, if we ever expand substantially then we'd def care more about the colo costs.

The cost difference is huge. Modern compute is just so much bigger than one would think. Hurricane Electric is incredibly cheap too. And Digital Realty in the city are pretty good. The funny thing is that the Monkeybrains guys will make room for you at $75/amp but that isn't competitive when a 9654 based system pulls 2+ amps at peak.

Still fun for someone wanting to stick a computer in a DC though.

Networking is surprisingly hard but we also settled for the cheapo life QSFP instead of the new Cisco switches that do 800 Gbps that are coming. Great writeup.

One that would be fun is about the mechanics of layout and cabling and that sort of thing. Learning all that manually was a pain in the ass. It's not just written down somewhere and I should have done it when I was doing it but now I no longer am doing it and so can't provide good photos.

Everyone should give AWS the middle finger and start doing this. Beyond cost, it's a matter of sovereignty over one's computing and data.

If this is a real market, I’d expect AWS to introduce S3 Junkyard with a similar durability and cost structure.

They probably still won’t budge on the egress fees.

>S3 Junkyard

There it is, the answer to how to mitigate brand damage when risking distance between themselves and some of those 9s.

we would be so down to buy s3 junkyard tbh we were going around begging various storage clouds to offer us this before giving up and building it ourselves

Where does one acquire 90M hours of video without being YouTube?

pr0n

"I swear I'm seeding those just so I get my ratio up" :)

Or the counter FB argument "It's not illegal because I'm NOT seeding."

Anywhere as long as you can avoid “legal/practice/business slog”. Success is defined by $1.5b settlements.

:) just kidding but also curious where besides torrents

My guess is automated surveillance, which is also where this whole play has to be headed.

Seems like that would be a good niche, not only for avoiding massive copyright considerations.

Also, it's some of the most boring footage where there's overwhelming amounts that's about the least desirable thing for humans to sit and watch every minute of.

Why send a human to do a machine's job?

“Solve computer use” and previous work is audio conversation model. How do these go together? Is the idea to replace keyboard and mouse with spoken commands? a la Star Trek

just general research work. Once the recipes are efficient enough the modality is a smaller detail.

On the product side we're trying to orient more towards 'productive work assistant' rather than the default pull of audio models towards being an 'ai friend'.

Make me transparent aluminum!

> We kept this obsessively simple instead of using MinIO or Ceph because we didn’t need any of the features they provided; it’s much, much simpler to debug a 200-line program than to debug Ceph, and we weren’t worried about redundancy or sharding. All our drives were formatted with XFS.

What do you plan to do if you start getting corruption and bitrot? The complexity of S3 comes with a lot of hard guarantees for data integrity.

our training stack doesn't make strong assumptions about data integrity, it's chill

Where does one get “90 million hours of video data”?

I’m also curious about this. I don’t recall seeing that mentioned in the article

Its in the first sentence: "We built a storage cluster in downtown SF to store 90 million hours worth of video data."

They were asking for the source of those data

/facepalm

For massive amounts of high-performance storage, the cloud is absolutely the most expensive option, by far. Even just 100+TB is ridiculously expensive on any cloud provider. If your company revolves around large amounts of data, it can make sense to keep it on-prem...

...but only if you compute the TCO. The bandwidth, peering, service contracts, available power, cooling, networking, rack capacity, half-decent smart hands, spare gear, etc, etc. The disks won't be the majority of your bill, and the logistics are difficult. It can still be cheaper than $CLOUD, but you have to deal with all the cost and complexity that comes with DIY, so do your homework first.

Wonder why everybody's first pick is CEPH which is known for being hard to optimize vs e.g. SeaweedFS

If I'd have to guess then I would think that Ceph is the only one who is truly open source and does not feature gate important parts to paid enterprise users.

I did go through this couple of years ago and we ended up with Ceph as well. Combine this with reusing existing hardware that was very suboptimal for Ceph in several ways, it was a pretty bad experience and in the end for our use case AWS was able to offer a good enough pricing that the performance and reliability of S3 was a better deal than managing it ourselves.

If I would do it again then I would make sure that I have the hardware setup that is ideal (plenty of SSD's for metadata, every spinning disk directly addressed as a single OSD, sound network topology and fast enough NIC's) and probably use Rook instead of cephadm. The monitoring, configuration and documentation side of Ceph is however still quite sad, it was really hard to figure out why something is slow and how to tune things faster.

That said, if the Enterprise options are performing better or you at least get good support for tuning and optimizing then the alternatives could be well worth consideration.

And how much did the training data cost?

The networking stuff seems....odd.

'Networking was a substantial cost and required experimentation. We did not use DHCP as most enterprise switches don’t support it and we wanted public IPs for the nodes for convenient and performant access from our servers. While this is an area where we would have saved time with a cloud solution, we had our networking up within days and kinks ironed out within ~3 weeks.'

Where does the switch choice come into whether you DHCP? Wth would you want public IPs.

> Wth would you want public IPs.

So anyone can download 30 PB of data with ease of course.

> Wth would you want public IPs.

Possibly to avoid needing NAT (or VPN) gateway that can handle 100Gbps.

I don't know what they're doing, but Mikrotik can perhaps route that → https://mikrotik.com/product/ccr2216_1g_12xs_2xq#fndtn-testr... and is about the cost of their used thing.

And I think this would be a banger for IPv6 if they really "need" public IPs.

Exactly what I came in to say, CCR2216 can do this for < $2k, and does it well.

No DHCP doesn't mean public IPs nor impact the need for NAT, it just means the hosts have to be explicitly configured with IP addresses, default gateways if they need egress, and DNS.

Those IPs you end up assigning manually could be private ones or routable ones. If private, authorized traffic could be bridged onto the network by anything, such as a random computer with 2 NICs, one of which is connected eventually to the Internet and one of which is on the local network.

If public, a firewall can control access just as well as using NAT can.

I know, I was specifically answering the question of "why the hell would you want public IPs".

I don't know why their network setup wouldn't support DHCP, that's extremely common especially in "enterprise" switches via DHCP forwarding.

Ok then yes I agree with you. That was weird

They didn't seem to want to use a router. Purpose-built 100 Gbps routers are a bit expensive, but you can also turn a computer into one.

Many switches are L3 capable, making them in effect a router. Considering their internet lines appear to be hooked up to their 100 Gbps switch, I'd guess this is one of the L3 ones.

It really feels like they wanted 30 PB of storage accessible over HTTP and literally nothing else. No redundancy, no NAT, dead simple nginx config + some code to track where to find which file on the filesystem. I like that.

This was not written by a network person, quite clearly. Hopefully it's just a misunderstanding, otherwise they do need someone with literally any clue about networks.

yeah misunderstanding we'll update the post-- separately it's true that we aren't network specialists and the network wrangling was prob disproportionately hard for us/ shouldn't have taken so long.

I assume your actual training is being done somewhere else? Did you try getting colocation space in the same datacentre as somewhere with the compute - it would have reduced your internet costs even further.

yeah the cost calculus is very different for gpus, it absolutely makes sense for us to be using cloud there. also hardly any datacenters can support the power density, esp in downtown sf

Yeh; one other thing - you list a separate management network as an optional - it's not optional! Under no circumstance must you expose the managemnt IPs of switches or the servers to the internet; they are, on average, about as secure as a drunk politician. Use a separate management net, make sure it's only securly accessed.

I understood that it's optional because they can walk down the road to the data center instead.

They mention plugging monitors in several times. I think I've only done that once in the last couple of years, when a firmware upgrade failed and reset the management interface IP.

yep this. we just turned off management

Massive props for getting it done anyway. For others reading: In general a switch should never run DHCPd, but will normally/often relay it for you, your arista's would 100% have supported relaying, but in this case it sounds like it might even be flat L2. Normally you'd host dhcpd on a server.

Some general feedback incase it's helpful.. -20K on contractors seems insane if we're talking about rack and stack for 10 racks. Many datacentres can be persuaded to do it for free as part of you agreeing to sign their contract. Your contractors should at least be using a server lift of some kind, again often provided kindly by the facility. If this included paying for server configuration and so on, then ignore that comment (bargin!).

-I would almost never expect to actually pay a setup fee (beyond something nominal like 500 per rack) to the datacentre either, certainly if you're going to be paying that fee it had better include rack and stack.

-A crash cart should not be used for a install of this size, the servers should be plugged into the network, and then automatically configured by a script/IPXE. It might sound intimidating or hard but it's not, doesn't even require IMPI (though frankly I would strongly, strongly recommend it, if you do't already have it). I would use managed switches for the management network too, for sure.

-Consider two switches, especially if they are second hand. The cost of the cluster not being usable for a few days while you source and install a replacement even here probably is still thousands.

-Personally not a big fan of the whole JBOD architecture and would have just filled by boots with single socket 4u supermicro chasis. To each their own, but JBOD's main benefit is a very small financial saving at the cost of quite a lot of drawbacks IMO. YMMV.

-Depending on who you use for GPUs, getting a private link or 'peering' to them might save you some cost and provide higher capacity.

-I'm kind of shocked that FMT2 didn't turn out much cheaper than your current colo, would expect less than those figures possibly with the 100G DIA included (normally about $3000/month no setup).

def agree on the setup fees, that was just a price crunch to get it done within the weekend. (too short-notice for professional services, too sensitive for craigslist, so basically just paying a bunch of folks we already knew and trusted)

for IPXE do you have any reference material you'd recommend? we had 3 people each with reasonably substantial server experience try for like 6 hours each and for whatever reason it turned out to be too difficult.

I assume it was their first time setting up ipxe? There's a lot of hang nails with it depending on the infra you're using it in.

For 10 racks it might not make sense.

I have done a ton of iPXE boot setups in the past. We use iPXE at our DC location for imaging, system recovery, etc. In fact, I just finished up a new boot image that creates a 100MB virtual floppy drive used for BIOS updates. Reach out and I can provide the entire setup if you like (pxe config files, boot loaders, scripts, etc).

Similarly I'm happy to share my ipxe scripts. It's just one of those things that you need to understand the fundamentals of before you start. It's about a hundred lines of bash to setup.

Honestly, with 10 servers, a pxe setup is probably overkill. If you're getting used servers (and maybe even if not), you might need to poke them with a KVM to set the boot options so that PXE is an option, and you might want to configure the BMC/IPMI from the console too, and then configure anything for serial over IPMI / bios console on serial ports... do that in your office, since your colo is across the street, and then you may as well do the install too. Then when you install, it should just work and crash cart if not. But, PXE is fun, so...

For PXE / iPXE, there's several stages of boot. You have your NIC's option rom, which might be, but probably is not iPXE. That will hit DHCP to get its own IP and also request info about where to pull boot files. You'll need to give it a tftp server IP and a filename. DHCPD config below

I server iPXE executables to non-iPXE. When iPXE starts up, it again asks DHCP, but now you can give it an http boot script. The simplest thing is to have something like

   kernel installer_kernel
   initrd installer_initrd
   boot

You can also boot isos, but that's a lot easier if you're in BIOS boot rather than UEFI. Better to practice booting kernels and initrds (unless you need to boot things like firmware update isos)

Then you'll have your installer (or whatever) booted, and you might have an unattended install setup for that, or you can just setup a rescue image that does dhcp (again!) and opens sshd so you can shell in and do whatever. Up to you.

the pxe part of my isc dhcpd config is:

   next-server 203.0.113.11;

   if exists user-class and option user-class = "iPXE" {
       option ipxe.no-pxedhcp 1;
       filename "http://203.0.113.11/tftpboot/menu.ipxe";
   } else {
       if option client-arch = 00:06 {
           filename "ipxe.efi-i386";
       } else if option client-arch = 00:07 {
           filename "ipxe.efi-x86_64";
       } else {
           filename "undionly.kpxe";
       }
   }

(This is mostly consoldidating bits and pieces from here [1] )

And I have those three files in the root of my tftp server. There's all sorts of other stuff you could do, but this should get you started. You don't really need iPXE either, but it's a lot more flexible if you need anything more, and it can load from http which is gobs faster if you have large payloads.

If you really wanted to be highly automated, your image could be fully automated, pull in config from some system and reconfigure the BMC while it was there. But there's no need for that unless you've got tons of servers. Might be something to consider if you mass replace your disk shelves with 4U disk servers, although it might not save a ton of time. If you're super fancy, your colo network would have different vlans and one of them would be the pxe setup vlan --- new servers/servers needed reimaging could be put into the pxe vlan and the setup script could move them into the prod vlan when they're done. That's fun work, but not really needed, IMHO. Semi-automated setup scales a lot farther than people realize, couple hundred servers at least. autopw [2] can help a lot!

[1] https://ipxe.org/howto/dhcpd

[2] https://github.com/jschauma/sshscan/blob/master/src/autopw

I mean generally above a certain size of deployment DHCP is much more trouble then it's worth.

DHCP is really only worth it when your hosts are truly dynamic (i.e. not controlled by you). Otherwise it's a lot easier to handle IP allocation as part of the asset lifecycle process.

Heck even my house IoT network is all static IPs because at the small scale it's much more robust to not depend on my home router for address assignment - replacing a smart bulb is a big enough event, so DHCP is solely for bootstrapping in that case.

At the enterprise level unpacking a server and recording the asset IDs etc is the time to assign IP addresses.

I have static, public IPs across 80 or so servers.

It gets set approximately once when the server's automated Ubuntu installation runs, and I never think about it.

> Where does the switch choice come into whether you DHCP?

Perhaps from home routers which include I've.

> Wth would you want public IPs.

Why wouldn't you? They have a firewall.

Why re-invent the wheel instead of using Lustre filesystem? It's easy to deploy on such a small filesystem; it is easy enough. POSIX interface, multiple clients, supports high-speed networking...

great write up, really appreciate the explanations / showing the process

As a fan of eBay for homelab gear, I appreciate the can-do scrappiness of doing it for a startup.

To adapt the old enterprise information infrastructure saying for startups:

"Nobody Ever Got Fired for Buying eBay"

DIY is always cheaper than paying someone else. Great write-up.

While I don't completely disagree with all the downsides of Ceph, it also sounds like they haven't heard of Croit. I set it up at my last company and it's amazing. It takes like 99% of the Ceph headaches away, plus you get Ceph experts to talk to.

i am still confused what their software stack is, they dont use ceph but bought netapp, so they use nfs?

The NetApps are just disk shelves, can plug it into a SAS controller and use whatever software stack you please.

but they have multiple head nodes, so its some distributed setup or just active/passive type thing?

I'm guessing the client software (outside the dc) is responsible for enumerating all the nodes which all get their own IP.

We have a custom barebones solution that uses a hashring to route the files!

I think each rack is one head node and several disk shelves (10?). No dual headed shelves.

Their electricity costs are $10K per month or about $120K per year. At an interest rate of 7% that's $1.7M of capital tied up in power bills.

At that rate I wonder if it makes sense to do a massive solar panel and battery installation. They're already hosting all of their compute and storage on prem, so why not bring electricity generation on prem as well?

Let's just say we're not seeing all of these sudden private nuclear reactor investments for no reason.

At 120K per year over the three year accounting life of the hardware, that's 360k... how do you get to 1.7M?

It seems unlikely to me that they'll never have to retrain their model to account for new data. Is the assumption that their power usage drastically drops after 3 years?

Unless they go out of business in 3 years that seems unlikely to me. Is this a one-off model where they train once and it never needs to be updated?

Cool write-up.

I do feel sorry for the friends that go suckered into doing a bunch of grunt work for free though

yeah that's why we started paying people near the second half- not super clearly stated in the blogpost, but the novelty definitely wore off with plenty of drives left to stack, so we switched strategies to get it done in time.

I think everyone who showed up for a couple hours as part of the party had a good time tho, and the engraved hard drives we were giving out weren't cheap :p

HDDs - are never one time costs. Do datacenters also offer ordering and replacing HDDs?

With 30PB it's likely they will simply let capacity fall as drives fail.

They apparently have zero need for redundancy in their use case, and the failure rate won't be high enough to take out a significant percentage of their capacity.

They offer replacing, yes, but normally expect you to order the new one. (Usually covered by a warranty, sent next business day.)

Is it correct that you have zero data redundancy? This may work for you if you're just hoarding videos from YouTube, but not for most people who require an assurance that their data is safe. Even for you, it may hurt proper benchmarking, reproducibility, and multi-iteration training if the parent source disappears.

Definitely much less redundancy, this was definitely a tradeoff we made for pretraining data and cost.

Did you do any kind of redundancy at least (eg: putting every 10 disks in RAID 5 or RAID Z1)? Or I suppose your training application doesn't mind if you shed a few terabytes of data every so often?

atm we don't and we're a bit unsure whether it's a free lunch wrt adding complexity. there's a really nice property of having isolated hard drives where you can take any individual one and `sudo mount` it and you have a nice chunk of training data, and that's something anyone can feel comfortable touching without any onboarding to some software stack

I wonder if snapraid would work for this. Especially if your data is mostly written once and then just read, it could be an easy way to add redundancy while keeping isolated individual drives.

How is/was the data written to disks? Something like rsync/netcat?

We use the same nginx rust server to do file writes, it's done via web requests

Would have been much easier and probably cheaper to buy gear from 45drives.

The biggest part that is always missing in such comparisons is the employee salaries. In the calculation they give $354k/year of total cost per year. But now add the cost of staff in SF to operate that thing.

someone has to go and power-cycle the machines every couple months it's chill, that's the point of not using ceph

So the drives are never going to fail? PSUs are never going to burn out? You are never going to need to procure new parts? Negotiate with vendors?

They mention data loss is acceptable, so im guessing they're only fixing big outages.

Ignoring failed hdds week likely mean very little maintenance.

This concern troll that everyone trots out when anyone brings up running their own gear is just exhausting. The hyperscalers have melted people’s brains to a point where they can’t even fathom running shit for themselves.

Yes, drives are going to fail. Yes, power supplies are going to burn out. Yes, god, you’re going to get new parts. Yes, you will have to actually talk to vendors.

Big. Deal. This shit is -not- hard.

For the amount of money you save by doing it like that, you should be clamoring to do it yourself. The concern trolling doesn’t make any sort of argument against it, it just makes you look lazy.

Very good point. There was something on the HN front page like this about self-hosted email, too.

I point out to people that AWS is between ten to one hundred times more expensive than a normal server. The response is "but what if I only need it to handle peak load three hours a day?" Then you still come out ahead with your own server.

We have multiple colo cages. We handle enough traffic - terabytes per second - that we'll never move those to cloud. Yet management always wants more cloud. While simultaneously complaining about how we're not making enough money.

I don't think the answer is so black-and-white. IMO This only realistically applies to larger companies or ones that either push lots of traffic or have a need for large amounts of compute/storage/etc.

But for smaller groups that don't have large/sustained workloads, I think they can absolutely save money compared to colo/dedicated servers using one of multiple different kinds of AWS services.

I have several customers that coast along just fine with a $50/mo EC2 instance or less, compared to hundreds per month for a dedicated server... I wouldn't call that "ten times" by any stretch.

Small companies should go for the likes of Hetzner/OVH, which is still 10+ times cheaper than AWS.

AWS is for anyone with a fear of committing to a particular amount of resource use, but once you've tried both and realised the price and performance differential, you realize you can easily way overcommit and still come out ahead, so it's not actually that scary. Plus, nobody's stopping you from continuing to spin up EC2s when your real servers are fully utilized.

Hard disagree... I think these black-and-white opinions are disingenuous, lack important nuance and are often just incorrect.

I even have customers on $3/mo EC2 instances... the cheapest dedicated server on OVH is still twenty times more expensive than that. I don't think there's any way to "come out on top" with OVH in that scenario, short of maybe claiming that the customer is somehow "doing it wrong" by only paying for what they need.

And yes hetzner/ovh have $3-4 cloud instances too, but now you're just directly competing with AWS and I don't see any benefit to call one any better than the other.

Thanks for this. I agree, there seems to be some sort of resistance to building and maintaining a CoLo infrastructure. In reality, it is not too difficult. As I mentioned above, spare parts on the shelve with the CoLo "remote hands" support and a good monitoring system can lessen the impact of almost any catastrophic issue.

For the record, I have built (and currently maintain) a number of CoLo deployments. Our systems have been running for +10 years with very little failure of either drives or PSUs. In fact, our PSU failure rate is probably 1 every 3-4 years, and we probably loose a couple of drives per year. All in all, the systems are very reliable.

You are under the assumption that only Ceph (and similar complex software) requires staff, whereas plain 30 PB can be operated basically just by rebooting from time to time.

I think that anyone with actual experience of operating thousands of physical disks in datacenters would challenge this assumption.

we have 6 months of experience operating thousands of physical disks in datacenters now! it's about a couple hours a month of employee time in steady-state.

How about all the other infrastructure. Since you are obviously not using the cloud, you must have massive amounts of GPUs and operating systems. All of that has been working together, it's not just keep watching for the physical disks and all is set.

Don't get me wrong, I buy the actual numbers regarding hardware costs, but in addition to that presenting the rest as basically a one man show in terms of maintenance hours is the point where I'm very sceptical.

oh we use cloud gpus, infiniband h100s absolutely aren't something we want to self-host. not aws tho, they're crazy overpriced; mithril and sfcompute!

we also use cloudflare extensively for everything that isn't the core heap dataset, the convenience of buckets is totally worth it for most day-to-day usage.

the heap is really just the main pretraining corpus and nothing else.

How is it going to work when the GPU is in the cloud and the storage is miles away in a local colo in SF down the street? I was under the impression that the GPUs has to go multiple times over the training dataset, which means transfer 30 PB multiple times in and out of the clouds. Is the data link even fast enough? How much are you charged for data transfer fees.

Not really. Have spare drives on the shelf and use the "remote-hands" feature from the CoLo provider. Just open a ticket to have the drive swapped. Pretty easy. For remote server connections just use IPMI/iKVM and iPXE. Again, not too difficult.

The biggest hurdle is getting a mgmt system in place to alert you when something goes wrong - especially at this size. Grafana, Loki, monit, etc are all good tools to leverage that provide quick fault identification.

Assuming that they end up hiring a full time ops person at 500k annually total costs (250k base for a data center wizard), then that's 42k extra a month, or ~$70k. Still 200k per month lower than their next best offering.

It's really not necessary.

I have four racks rather than ten, and less storage but more compute. All purchased new from HP with warranties.

Ordering each year takes a couple of days work. Racking that takes one or two.

Initial setup (seeing differences with a new generation of server etc and customizing Ubuntu autoinstallation) is done in a day.

So that's a week per year for setup.

If we are really unlucky, add another week for a strange failure. (This happened once in the 10 years I've been doing this, a CPU needed replacement by the HP engineer.)

I replaced a couple of drives in July, and a network fibre transceiver in May.

The biggest part missing from the opposing side is: Their view is very much rooted in the pre-Cloud hardware infrastructure world, where you'd pay sysadmins a full salary to sit in a dark room to monitor these servers.

The reality nowadays is: the on-prem staff is covered in the colo fees, which is split between everyone coloing in the location and reasonably affordable. The software-level work above that has massively simplified over the past 15 years, and effectively rivals the volume of work it would take to run workloads in the cloud (do you think managing IAM and Terraform is free?)

> do you think managing IAM and Terraform is free?

No, but I would argue that a SaaS offering, where the whole maintenance of the storage system is maintained for you actually requires less maintenance hours than hosting 30 PB in a colo.

In terraform you define the S3 bucket and run terraform apply. Afterwards the company's credit card is the limit. Setting up and operating 30 PB yourself is an entirely different story.

yeah colo help has been great, we had a power blip and without any hassle they covered the cost and installation of UPSes for every rack, without us needing to think abt it outside of some email coordination.

Small startup teams can sometimes get away with datacenter management being a side task that gets done on an as-needed basis at first. It will come with downtime and your stability won't be anywhere near as good as Cloudflare or AWS no matter how well you plan, though.

Every real-world colocation or self-hosting project I've ever been around has underestimate their downtime and rate of problems by at least an order of magnitude. The amount of time lost to driving to the datacenter, waiting for replacement parts to arrive, and scrambling to patch over unexpected failure modes is always much higher than expected.

There is a false sense of security that comes in the early days of the project when you think you've gotten past the big issues and developed a system that's reliable enough. The real test is always 1-2 years later when teams have churned, systems have grown, and the initial enthusiasm for playing with hardware has given way to deep groans whenever the team has to draw straws to see who gets to debug the self-hosted server setup this time or, worse, drive to the datacenter again.

> The amount of time lost to driving to the datacenter, waiting for replacement parts to arrive, and scrambling to patch over unexpected failure modes is always much higher than expected.

I don't have this experience at all. Our colo handled almost all work. the only time i ever went to the server farm was to build out whole new racks. Even replacing servers the colo handled for us at good cost.

Our reliability came from software not hardware, though of course we had hundreds of spares sitting by, the defense in depth (multiple datacenters, each datacenter having 2 'brains' which could hotswap, each client multiply backed up on 3-4 machines)...

servers going down were fairly common place, servers dying were commonplace. i think once we had a whole rack outage when the switch died, and we flipped it to the backup.

Yes these things can be done and a lot cheaper than paying AWS.

> Our reliability came from software not hardware, though of course we had hundreds of spares sitting by, the defense in depth (multiple datacenters, each datacenter having 2 'brains' which could hotswap, each client multiply backed up on 3-4 machines)...

Of course, but building and managing the software stack, managing hundreds of spares across locations, spanning across datacenters, having a hotswap backup system is not a simple engineering endeavor.

The only way to reach this point is to invest a very large amount of time into it. It requires additional headcount or to put other work on pause.

I was trying to address the type of buildout in this article: Small team, single datacenter, gets the job done but comes with tradeoffs.

The other type of self buildout that you describe is ideal when you have a larger team and extra funds to allocate to putting it all together, managing it, and staffing it. However, once you do that it's not fair to exclude the cost of R&D and the ongoing headcount needs.

It's tempting to sweep it under the rug and call it part of the overall engineering R&D budget, but there is no question a large cost associated with what you described as opposed to spinning up an AWS or Cloudflare account and having access to your battle-tested storage system a few minutes later.

not caring about redundancy/reliability is really nice, each healthy HDD is just the same +20TB of pretraining data and every drive lost is the same marginal cost.

When you lose 20 TB of video, where do you get 20 TB of new video to replace it?

To be fair, what's described here is much more robust than what you get with a simple AWS setup. At a minimum that's a multi-region setup, but if the DCs have different owners I'd even compare it to a multi-cloud setup.

not multi-cloud but multi-infrastructure. Yes there were naturally different owners since there were colos in NY, west coast, netherlands, etc.

fwiw our first test rack has been up for about a year now and the full cluster has been operational for training for the past ~6 months. having it right down the block from our office has been incredibly helpful, I am a bit worried abt what e.g. freemont would look like if we expand there.

I think another big crux here is that there isn't really any notion of cluster-wide downtime, aside from e.g. a full datacenter power outage (which we've had ig, and now have UPSes in each rack kindly provided and installed by our datacenter). On the software/network level the storage isn't really coordinated in any manner, so failures of one machine only reflect as a degradation to the total theoretical bandwidth for training. This means that there's generally no scrambling and we can just schedule maintenance at our leisure. Last time I drew straws for maintenance I clocked a 30min round-trip to walk over and plug a crash cart into each of the 3 problematic machines to reboot and re-intialize and that was it.

Again having it right by the office is super nice, we'll need to really trust our kvm setup before considering anything offsite.

For drive issues, this is easy. Have a stack of replacements on hand and just open a "remote-hands" ticket with the CoLo provider to swap out the drive. This can usually be done in 1-2hrs from opening the ticket.

For server issues; again, pretty easy. Just use iKVM/IPMI and iPXE to diagnose a faulty server. Again, using "remote-hands" from the CoLo provider can help fix problems if your staff does not have the skills.

In my experience, the issues that take 80% of your time are the unexpected edge cases, not the easy fixes.

Swapping drives is basically the easiest fix. The issues that cause the most problems are the hard to diagnose ones like the faulty RAM that flips a bit every once in a while or the hard drive controller that triggers an driver bug with weird behavior that doesn’t show up in the logs with anything meaningful.

Sure, but realistically, how often does this really happen? I have probably replaced 3 or 4 DIMMs over the past few years. Hardware is very reliable these days.

I've built and maintained similar setups (10PB range). Honestly, you just shove disks into it, and when they fail you replace them. You need folks around to handle things like controller / infrastructure failure, but hopefully you're paying them to do other stuff, too.

Great piece, thanks for the write up.

damn this is cool as hell. estimate on the maintenance cost in person-hours/month?

Around 2-5 hours/month, mostly powercycling the servers and replacing hard drives

You should be able to power cycle the servers from their management interfaces.

(But I have the luxury of everything being bought new from HP, so the interfaces are similar.)

Aren't those netapp shelves pretty old at this point? See a lot of people recommending against them even for homelab type uses. You can get those 60 drive SuperMicro JBODs for pretty cheap now, and those aren't too old, would have been my choice.

Plus, the TCO is already way under the cloud equiv. so might as well spend a little more to get something much newer and more reliable

yeah it's on the wishlist to try

Thanks to op for actually replying to the various comments here - really appreciate that (and for the initial of course!)

IPMI is great and all, but I still prefer serial ports and remote PDUs. Never met a BMC I could trust.

Try Lenovo. Their BMCs Don't Suck (tm).

Serial over IPMI, plus ipmi power control is pretty good when it works. Supermicro X10 and newer was pretty nice. X9 and X8 not as nice; it's not helpful when the serial over ipmi drops during reboot and doesn't come back in a reasonable amount of time, and then the graphical mode needs ancient java webstart with os and platform specific jni, oof.

the doodles are great

Thanks! Lots of hard work went into them.

how long do you think it'll be before you fill all of it and have to build another cluster LOL

Already filled up and looking to possibly copy and paste :)

So, others have asked, and I'm curious myself are you sourcing the videos yourselves or third parties?

My guess would be they are running some dummy app like quote of the day or something and it records the screen at 1fps or so.

Just wanted to say, thanks for doing this! Now the old rant...

I started my career when on-prem was the norm and remember so much trouble. When you have long-lived hardware, eventually, no matter how hard you try, you just start to treat it as a pet and state naturally accumulates. Then, as the hardware starts to be not good enough, you need to upgrade. There's an internal team that presents the "commodity" interface, so you have to pick out your new hardware from their list and get the cost approved (it's a lot harder to just spend a little more and get a little more). Then your projects are delayed by them racking the new hardware and you properly "un-petting" your pets so they can respawn on the new devices, etc.

Anyways, when cloud came along, I was like, yeah we're switching and never going back. Buuut, come to find out that's part of the master plan: it's a no-brainer good deal until you and everyone in your org/company/industry forgets HTF to rack their own hardware, and then it starts to go from no-brainer to brainer. And basically unless you start to pull back and rebuild that muscle, it will go from brainer to no-brainer bad deal. So thanks for building this muscle!

I'm not op, but thanks for this. Like I mentioned in another comment, the wholesale move to the cloud has caused so many skills to become atrophied. And it's good that someone is starting to exercise that skill again, like you said. The hyperscalers are mostly to blame for this, the marketing FUD being that you can't possibly do it yourself, there are too many things to keep track of, let us do it (while conveniently leaving out how eye-wateringly expensive they are in comparison).

The other thing the cloud does not let you do is make trade offs.

Sometimes you can afford not to have triple redundant 1000GB network or a simple single machine with raid may have acceptable down time.

yeah this

it means that even after negotiating much better terms than baseline we run into the fact that cloud providers just have a higher cost basis for the more premium/general product.

we're in a pretty unique situation in that very early on we fundamentally can't afford the hyperscaler clouds to cover operations, so we're forced to develop some expertise. turned out to be reasonably chill and we'll prob stick with it for the foreseeable future, but we have seen a little bit of the state-creep you mention so tbd.

Yeah from memory on-prem was always cheaper, it just removed a lot of logistic obstacles and made everything convenient under one bill.

IIRC the wisdom of the time cloud started becoming popular was to always be on-prem and use cloud to scale up when demand spiked. But over time temporarily scaling up became permanent, and devs became reliant on instantly spawning new machines for things other than spikes in demand and now everyone defaults to cloud and treats it as the baseline. In the process we lost the grounding needed to assess the real cost of things and predictably the cost difference between cloud and on-prem has only widened.

> IIRC the wisdom of the time cloud started becoming popular was to always be on-prem and use cloud to scale up when demand spiked.

I've heard that before but was never able to make sense of it. Overflowing into the cloud seems like a nightmare to manage, wouldn't overbuilding on-prem be cheaper than paying your infra team to straddle two environments?

As someone with experience with a company that did hybrid, I’ll say: it only makes sense if your infra team deeply understands computers.

The end state is “just some IaC,” wherein it doesn’t really matter to anyone where the application lives, but all of the underlying difficulties in getting to that state necessitate that your team actually, no-shit knows how distributed systems work. They’re going to be doing a lot of networking configuration, for one, and that’s a whole speciality.

I've setup on-prem environments that would automatically and transparently spill workload to the cloud when we ran out of on-prem capacity. The prerequisite is that your operations people need to have strong automation skills, there can't be any human button-pushers in the loop, but it really isn't that much work nor does it require unusual technical skill if you have a competent operations environment. Once everything is wired up, it mostly just works. Even the devs often don't know whether their workloads are running on-prem or in the cloud.

An under-rated aspect of this is that it provides detailed data for planning the expansion of the on-prem environment, including changes in how the hardware is being used.

My experience is that this is a good model. On-prem is about 1/3 the cost of the cloud, fully burdened, in my experience but being able to transparently spill to the cloud mitigates the capacity and supply chain risks that come with on-prem.

It is effectively a cheap insurance policy.

Wanna see us do it again?

Docker is amazing for forcing the machines not to be pets, seriously, a racked sever is just another K3 or K8 node (or whatever) and doesn't get the choice or ability of being petted. It's so nice. You could maybe of said the same about vm's but not really, the VM just became the pet, OK you could at least image/snapshot it but it's not the same.

I've found docker is as of a monstrous pet.

Docker is a monster that you have to treat as a pet. You've still got to pet it through stages of updating, monitoring, snapshots and networking. When the internal system breaks it's no different to a server collapsing.

Snapshots are a haircut for the monster, useful but can make things worse.

Not in my experience, super easy to setup a K3s cluster in a single rack. Certainly less hassle than VMWare was or XEN ever was.

I find the same with Systemd and Docker.

Some can tame the beast, for me it's always a fight until one of us holds down the power button.

It’s interesting everyone having different experiences and those experiences drive what they do.

I would never dream of running Docker in production. It seems so overly complicated. Also, since day one, I could never understand using a public registry for mission critical stuff. When I was learning Docker, I would unplug the network cable so I wouldn’t accidentally push my container online somewhere with all my data.

I totally get the concept at scale. I also get the concept of just shipping an application in a container. I also get the concept of self-hosting of just give me the container so I don’t have to think about how it all works.

However, the complexity of building the container, cleanup, deleting entries, environment variables, no SSH availability, even on Railway in the beginning, ambiguous where your container needs to be to be to even get it somewhere. Public registry or private registry.

Certainly most of it is my lack of knowledge of not sticking with it.

Just give me a VM and some firewall rules. Cloning VMs can be automated in so many different ways.

/rant

I agree with you, but I also don’t do webdev. Docker seems neat, I’ve dabbled just to understand the stack and how it works. Not much of a container person I realized. Closest I get is spinning out yocto images and flashing them to hardware. Same image every time with updated versions of software. So maybe kind of like docker in the abstract sense, I suppose.

I’m mid-way through my career at this point and I’m hoping to skip the web/cloud bit, I just don’t enjoy it as much as I do hw/sw integrations.

Any startup that has enough money to casually buy a two-letter domain name has too much money, period. Kind of like counting the number of Aeron chairs at startups of old. Not a good sign.

It's a .inc domain name, are those worth anything?

Looks like unregistered two letter .inc domains are going for $2300/yr. Certainly <5% of the cost of a single developer.

it's .inc... those aren't expensive

AWS obviously does the same but better. That's why they are so rich. Their cost is a tiny percentage of their revenue. They buy cheap servers, and then run lots of vms on them. Each of which delivers 10s/100s of $ per month. That server pays for itself in revenue within weeks/months. And it will be in service until it stops working which could be over five years. Same with storage, networking, gpus, etc.

They've spent years optimizing everything so their monthly costs are going to be much lower than what these guys managed on their first attempt. They'll be using less energy. They run their own internet backbones and infrastructure, they design their own hardware and source components directly from the best suppliers, they have exclusive deals with energy providers, etc. Every thing these guys did, AWS does way better. And yet they charge 40x more. AWS at cost price would probably be 60-80x less than what they charge; if not more. Cloudflare undercuts them a bit because they are smaller but they can do the same things. So do MS, Google, and everybody else.

This market is ripe for disruption. There should not be a need to shovel hundreds of billions per year into AWS revenue for the industry. The same business operating at 20% margins would be a game changer. And most of this stuff is commodity stuff. Why is there not more competition in this space driving pricing down aggressively? What's keeping competitors off the market?

Inertia. It's the new 'nobody gets fired for buying..'

A previous project I worked on had relatively little traffic, and AWS costs were rather insane for that.

I proposed exploring OVH or DO and probably get costs down to 2 digits per month. Upper management would hear nothing of it - AWS was what they wanted, costs be damned. They were more protecting their own jobs than making a technical decision, I think.

Unless the savings would be more than 100k Eur / 300k++ USD (I.e. total cost of one employee, it's not really worth it. Even then, moving to new infrastructure carries high risk for business disruptions which can cause an even bigger dip in revenue.

The cloud providers have definitely optimized their pricing for maximum profit extraction. Costs are high, and in many cases it's not high enough to actually warrant changing infrstructure to cheaper alternatives.

Sticking with AWS / Azure / GCP carries other benefits, too. You're more likely to find engineers who are experienced with those cloud platforms over, say, OVH.

AWS costs are insane for every project.

> Upper management would hear nothing of it

No one knows how to plan ahead any more. It's all "agile" and hardware (and budgeting for it) isnt something most in management are capable of doing any more.

There is also then justifying the CapEx on a 5 year amortization schedule... the thing is even if you borrow that money at current rate (7 percent) you can still come out far ahead of AWS... It's a lot of math, and a lot of accounting (and the accountability that comes with it).

Your average CTO just doesn't have these skills.

> AWS at cost price would probably be 60-80x less than what they charge; if not more.

If you look at https://ir.aboutamazon.com/news-release/news-release-details... , it says in 2024,

> AWS segment sales increased 19% year-over-year to $107.6 billion.

> AWS segment operating income was $39.8 billion, compared with operating income of $24.6 billion in 2023.

So about 59% margin, relative to costs. Everybody undercutting AWS is likely doing so at close enough to 20% margins that it makes no sense to fund a startup in the same space.

AWS is everything from GPU farms and AI services to S3.

I would be shocked if S3 had less than a 100% margin at sticker price.

These guys had one of the most important prerequisites to make going on-prem easy - they didn't care about cross-site or reliability.

> AWS segment operating income was $39.8 billion

keep in mind that cost there is likely to also be including personnel. probably a significant fraction if you consider how many employees amazon's aws division has.

> This market is ripe for disruption. here should not be a need to shovel hundreds of billions per year into AWS revenue for the industry. The same business operating at 20% margins would be a game changer.

Honestly, I don't understand this line of thinking. You're not alone in it either, but it always reads so naive.

Like you can magically hand wave or it'd be so easy and get a competitor who can do it just as well and/or cheaper than AWS. But somehow these statements seem to ignore that you can't. Otherwise Digital Ocean would've, or cloudflare or <name-your-linnode-rackspace-startup>.

The industry funnels billions to become vendor locked in because AWS is simply that good - bar none.

Even Google kept considering killing GCP for years. Meta is going to burn a bunch more billions on cartoons that play in your glasses before they get into cloud hosting and the other existing competitors have huge issues crossing the chasm of "everything is an API" that AWS has.

There's a long tail of smaller clouds: Digital Ocean, Oracle, IBM, Linode/Akamai, not to mention server providers like OVH and Hetzner, and not to mention Chinese clouds like Tencent and Alibaba (which both have US regions), not to mention PaaS providers who run on their own hardware like Fly.io.

I think it's very hard to make a claim that the market is not price-competitive. The problem is that most decision makers don't actually prioritize price, they prioritize support and the larger ecosystem. It's easy to find engineers with experience on the big 3 clouds and they will be able to pick up where the previous engineers left off. No CTO goes to sleep worrying about whether they being vendor-locked into AWS will result in catastrophic business failure tomorrow due to catastrophic hardware failure. There is a larger ecosystem - observability, FinOps tooling, cloud security tooling, managed databases, that are virtually guaranteed to support AWS, sometimes support GCP and Azure, and almost never support any of the other clouds.

It's questionable whether the current situation is really due to companies like Oracle and IBM being unable to compete on price and make strategic partnership deals to build out ecosystem support for their clouds. I think it's more likely that AWS/GCP/Azure "won" the cloud market, and that if regulators were worth a damn, they'd start to address the market concentration instead of ignoring it.

So now you have all

- your storage in one place

- you own all backup,

-- off site backup (hot or cold)

- uptime worries

- maintenance drives

-- how many can fail. before it is a problem

- maintenance machines

-- how many can fail. before it is a problem

- maintenance misc/datacenter

- What to do the electricity is cut off suddenly

-- do you have a backup provider?

-- disel generators?

-- giant batteries?

-- Will the backup power also run cooling?

-natural disaster

-- earthquake

-- flooding

-- heatwave

- physical security

- employee training / (esp. if many quit)

- backup for networking (and power for it)

- employees on call 24/7

- protection against hacking

+++++

I agree that a lot of cloud providers overcharge by a lot, but doing it all yourself gives you a lot of headaches.

co-hosting would seem like a valuable partial mitigator.

Most of these come from your colo provider (including a good backup power and networking story), and you can pay remote hands for a lot of the rest.

Things like "protection from hacking" also don't come from AWS.

Garbage in, garbage out, 30 petabyte edition

Used Disks, No DR, not exactly a real shoot out.

True, though this is specifically for pretraining data (S3 wouldn't sell us used disk + no DR storage).

You're in a seismically active part of the world. Will the venture last in a total loss scenario?

We're currently 1/1 for the recent 4.3 magnitude earthquake (though if SF crumbles we might lose data)

4.3 is a baby quake. I'd hope that you'd be 1/1!

They spent $300,000 on drives, with AWS they would have spent 4x that PER MONTH. They're already ahead of the cloud.

AWS/cloud doesn't factor into my question what so ever. Loss of equipment is one thing. Loss of all data is quite a different story.

I do appreciate the scrappiness of your solution. Used drives for a storage cluster is like /r/homelab on steroids. And since it's pretraining data, I suppose data integrity isn't critical.

Most venture-backed startups would have just paid the AWS or Cloudflare tax. I certainly hope your VCs appreciate how efficient you are being with their capital :)

worth stressing that we literally could not afford pretraining without this, approx our entire seed round would go into cloud storage costs

$125/disk, 12k/mo depreciation cost which i assume means disk failures, so ~100 disks/mo or 1200/yr, which is half of their disks a year - seems like a lot.

no, we wanted to be conservative by depreciating somewhat more aggressively than that. we have much closer to 5% yearly disk failure rates.

It's an accounting term. You need to report the value of assets of your company each reporting cycle. This allows you to report company profit more accurately since the 2400 drives aren't likely not worth what the company originally paid. It's stated as a tax write-off but people get confused with that term (they think X written off == X less tax paid). It's better to correctly state it as a way to more accurately report profit (which may end up with less company tax paid but obviously not 1:1 since company tax is not 100%).

So anyway you basically pretend you resold the drives today. Here they are assuming in 3 years time no one will pay anything for the drives. Somewhat reasonable to be honest since the setup's bespoke and you'll only get a fraction of the value of 3 year old drives if you resold them.

oh i see, thanks! i might be too used to reading backblaze reports :p

Reply on news.ycombinator.com