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Comment by bsder | Hacker News Reader

Z ... F ... S.

And at least Raid-Z. Raid-5 and Raid-6 are now at probability of failure levels that your rebuild is likely to throw an error.

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ZFS is great, but won't help if there's a power surge that fries all the disks at once. To prevent that you'll want to store snapshots remotely somewhere.

To prevent that you'll want to s̶t̶o̶r̶e̶ ̶s̶n̶a̶p̶s̶h̶o̶t̶s̶ ̶r̶e̶m̶o̶t̶e̶l̶y̶ ̶s̶o̶m̶e̶w̶h̶e̶r̶e̶.̶ use a surge protector

Don't forget to replace your surge protector on an annual basis (or more frequently if you have really dirty power). Also, you can have a nasty fault in your PSU that fries everything also (If anyone knows of a surge protector that sits between the power supply and the motherboard, I'd really like to get one).

> (If anyone knows of a surge protector that sits between the power supply and the motherboard, I'd really like to get one)

I think the best you can do is just get a top-quality power supply. SeaSonic will sell you a ridiculously overengineered box with a 12-year warranty for $160; it's guaranteed to have a longer useful lifetime than any other component in your computer, probably even including the case itself.

Just use a surge protector literally right next to your PSU.

Cheap whole house surge protectors are pretty much useless. It will work for a few times, but the MOVs will degrade and fail pretty quickly. Every time a big inductive load switches on or off its going to cause a voltage spike that is going to trip the MOVs. or the MOV's Trip voltage is so high (to avoid quick degration) that they really don't provide any protect. Really a good whole house protector needs to use SADs (Silicone Avalance Diodes) or a passive LC filter. Transtector, Thor Systems (SADs) or Pricewheeler (LC Filter). These protectors can take many more surge hits than the ones you listed above. Why whole house Surge protectors don't work.https://zerosurge.com/wp-content/uploads/2016/10/USTech.pdfE... with a whole house protector it still would be a good idea to use point of use surge protectors. Since the surge has to reach the Whole House protector before it can be clamped. Surges can reach your electrical devices faster than a whole house protector can clamp. It only takes a few nanoseconds to destroy a microchip. For instance say you have a vacuum cleaner plugged into the same circuit your computer is connected to. the vacuum cleaner jams, causing a surge that will hit your computer (since it closer) than the whole house proetector is (down in your basement).

Source: comment section on https://www.youtube.com/watch?v=6PqO0aQaGDY

True story: I've seen Raid5 not recovering after a simple power loss. Software was working but couldn't build it up. Fortunately, we didn't have to dig further than wiping it.

Exactly, my solution right now is to create encrypted backups of my raid-z2 FreeNAS instance (protected by a UPS) and then have a nightly cronjob copy the backup to a 4TB external hard drive using duplicacy (https://duplicacy.com). This drive gets rotated with another drive stored locally within the house, but in a fireproof and fairly waterproof location, then every 3 weeks I rotate the oldest drive out to a safety deposit box and bring the current drive in the safety deposit box back into the in-house rotation. Call me paranoid, but for me it's worth the peace of mind and ease of local restoration. Once you get in the routine it's really not that much work at all. :-)

Sure. Encrypted ZFS with FreeBSD, have a power loss, goodbye data.

Should have read the manual though, it does tell you to make a backup of certain data ranges in case of encrypted ZFS for this specific case, so it's partly my fault.

That said, I'm using ZFS ever since, but on top of LUKs with linux.

So LUKS is more resilient than native ZFS encryption to power loss?

Encrypted ZFS with FreeBSD is not actually native ZFS encryption, it uses GELI to handle the encryption part (which may be why it's bad at handling power losses).

Ah, for some reason I was thinking that FreeBSD's implementation of OpenZFS had native encryption.

Hopefully someday. https://github.com/openzfs/openzfs/pull/489

Do you have more information on this?

I've just rebuilt my home server/nas going from 2x3tb disks in a mirror no encryption to 4 x 4tb disks in a striped mirror with native ZFS encryption on ZOL.

Most of my data is read only media content, 90% read use which is also extremely low io wise and write is only when adding new media. I was thinking power loss would only be an issue loosing data that is currently being written so would not corrupt the entire zpool?

If native ZFS encryption can lead to loosing a zpool on powerloss I might look in to buying a used cheap Dell r210 ii, stick two 8tb drives in as a mirror then stick it in a collocation data center and use native zfs send/recv incremental snapshots for offsite. Looks to be cheaper then rsync.net $30 per TB/month for ZFS when you got 2-3TB+, also can do the initial sync locally. Still looking at $700+ a year after initial hardware costs.

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