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Comment by jamwt | Hacker News Reader

Yes, a 1PB+ failure domain only made sense because Magic Pocket is very good at automatic cluster management and repair.

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Are you using spindle or ssd or flash? (admittedly I dont know if you consider flash and ssd to be the same)

What is your price per GB raw?

> Are you using spindle or ssd or flash? (admittedly I dont know if you consider flash and ssd to be the same)

We have flash caches (NVMe) in the machines, but the long-term storage devices are spindle--PMR and SMR.

> What is your price per GB raw?

I cannot disclose, exactly, but it is well below any other public price I've seen.

So NVMe is "ready for production"? Do you think you'd use it at home, or only in the enterprise?

I mean, if at home you need 400k IOPS, 1GB/s of writes, and 2.2GB/s of reads... go for it! I sure don't, but more power to you. :-)

NVMe's lower latency is great. I've never really known how "slow" regular SATA/SAS SSD's were until I used NVMe ones.

I'm tempted to get one and set it up as some kind of cache in my NAS. I'm already in silly territory with it now, anyway. 1GB/s of writes sounds crazy though - I haven't got anything that can write to it that fast!

I have a PCIe NVMe card (with a Samsung 950 pro M.2 in it) in my home server, which serves as an L2arc device for a ZFS pool. It is pretty nice. Runs a bit warm though.

We are now well offtopic but I've seen some advice recently that advises using an SLOG rather than L2ARC for a home NAS.

I think that a home nas would have a lot of async writes and very few/none sync writes. So a ZIL dedicated device (the SLOG) is not really useful/helpful. I'm not sure even if you really need an L2ARC device, just slap 8/16Gb of RAM on it and you will be happy...

Obviously if you are playing seriously with VMs and databases and whatever else both of those (SLOG/L2ARC) may become important for you, I'm going for the "i'm just using this to store my raw-format photos, backups for the taxes and other big files" kind of usage here. :)

You don't have any contact details but I'd definitely like to talk to you more about home NAS.

Aside, Google Cloud has NVMe available on almost all machine types if you want to play with it [1].

[1] https://cloud.google.com/compute/docs/disks/local-ssd

I put it in production, and it's something else. Whether I'd use it at home depends entirely on how rich I feel I am ;)

We have been primarily using Intel NVMe storage for our database servers since fall of 2014 with no major complaints. Our high end desktop/laptop systems are also using the latest Samsung NVMe M.2 drives which are screaming fast.

Just to put a number to "screaming fast", 2.5 GB/s sequential reads averaged across the entire drive on a Samsung 950 Pro NVMe SSD: https://pbs.twimg.com/media/CaMhc2oVAAE4q3q.jpg:large

Surely it's the other way round?

That is, the better your software can handle repair, the smaller your failure domain can be?

A larger failure domain would only make sense if you wanted to minimize the compute required per unit stored?

We do want to minimize that--compute costs money, and storage is irreducible. But you can only reduce aggressively if your larger distributed system is great at repairs, since the failure of a single box kicks off 1PB of repair activity!

Thanks, do you have a time lapse backup of data in Magic Pocket? For example, in case of software error?

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