My one BB question is how many data centers do they have? I know they have great sharing tech to keep data online if a pod or two goes down, but how many physical locations do they run?
> how many physical locations to they run?
Two separate datacenters in the Sacramento (California) region, and one in Phoenix (Arizona). We are trying to open a European (Netherlands) datacenter this month or next month.
However, unless you take explicit action to copy your data to two datacenters, any one file (or piece of file) is in exactly one datacenter. We believe the data to be extremely DURABLE (survive), but if your strategy is to "host content" in a highly available fashion where people will die if your content is offline for an hour, we recommend you use two different providers with some sort of fail over. Another alternative is to use a CDN (Content Delivery Network) in conjunction with Backblaze. You can find out more info here: https://www.backblaze.com/b2/solutions/content-delivery.html
For backups, Backblaze advocates for a 3-2-1 backup strategy. https://www.backblaze.com/blog/the-3-2-1-backup-strategy/ This is where you keep 3 copies of your data, 2 on site, and 1 in the cloud.
The exact system for how we achieve high durability is described in this blog past: https://www.backblaze.com/blog/vault-cloud-storage-architect... where any one file is striped across 20 separate computers in 20 separate locations in the one datacenter, where we can entirely lose any 3 computers and the data is completely fine and available.
We are COMPLETELY transparent on how we calculate the durability, we do the math (including the assumptions) in this blog post: https://www.backblaze.com/blog/cloud-storage-durability/
EDIT: Apparently GCS has this feature built in. Did not know, very cool!
But anyway why should I have to build it on top of the provider's offering - why wouldn't they provide georedundancy for me? It seems like a truly basic thing to expect for a backup solution?
But I'm not an expert in this area.
https://cloud.google.com/storage/docs/locations
/I work for Google/
You can setup a bucket to replicate a bucket in another region, at double the storage costs plus bandwidth charges.
Do your durability metrics take datacenter failure or human error into account?
Datacenter failures are rare, but they do happen and can cause data loss if all of your data is in that data center.
Likewise, human error can cause cascading failures across a datacenter (or beyond) if there are no firewalls between zones that prevent a single person/command/software update from affecting all copies of the data.
https://www.datacenterknowledge.com/microsoft/azure-outage-p...
“ but in this instance, temperatures increased so quickly in parts of the data center that some hardware was damaged before it could shut down" ... "A significant number of storage servers were damaged, as well as a small number of network devices and power units.”
Given the fact that Azure lost a datacenter with this failure mode, I don't think it's in the "likelihood of an asteroid destroying Earth within a million years" ballpark.
Their durability page doesn't really clear it up, they say "Because at these probability levels, it’s far more likely that ... Earthquakes / floods / pests / or other events" known as “Acts of God” destroy multiple data centers". But from the post above: "any one file (or piece of file) is in exactly one datacenter."
So it doesn't take multiple datacenter failures to lose data, just one unless you explicitly copy your data to multiple datacenters.
You don't have to be amazed. Watch and learn. They do it because it's good marketing and results in business. The catchy headline got me to click and read. It got the name 'backblaze' into my head one more time. It makes them appear relevant and enhances the brand.
Since Yev is probably reading the comments I will offer another topic that would be interesting.
Do a post on erasing data from SSD's and then being able to recover that data. There was a well known paper by some academics years ago about this. The result was YMMV depending on the drive, controller etc. That would make an interesting blog post.
My main concern with this type of services is, are they just reselling S3 and hoping people will never use their quota (something I don’t see as sustainable business model).