On 2018-08-27 09:24 AM, Giles Orr via talk wrote:
On Sat, 25 Aug 2018 at 14:21, David Mason via talk <talk@gtalug.org <mailto:talk@gtalug.org>> wrote: This system is <5 years old, and at the time was kind-of leading edge. so I’m not worried about that. It’s a 4.4Tb raidz2 at 64% and has performed flawlessly. Unfortunately I don’t really have the time to do any serious digging right now, either.
How do others backup their ZFS systems? Getting a 4T external drive doesn’t seem like the best plan, but maybe there isn’t any other choice.
In my case I built a secondary NAS and disk array, and do regular 'zfs snapshots' and 'zfs sends'. In recent history I've started using zfs-snap-manager to automate that. https://github.com/khenderick/zfs-snap-manager It's a rather coarse tool... doesn't support automate snapshots more frequent then once a day, but will happily send over any you've made manually (via a cron job or alternative method). Currently the developer has only packaged it for Arch. But I've built an rpm spec file for it. Attached.
Actually, that sounds like a really good plan. In fact, buy two so you can do rotating backups. Think about your alternatives - about the only one that occurs to me is a tape drive. There used to be consumer-grade tape backups, but they don't exist anymore and I'd argue this is no longer a viable solution outside the data centre.
Buying external hard drives is a really good idea: they're dirt cheap (at least compared to the alternative - failure of your primary).
I agree with Giles. If you don't want to drop the coin on a second NAS, this is a very usable strategy. Get a 6 or even 8TB disk, format it as a ZFS pool and turn on zfs's block compression, and set copies to '2'. zfs set compression=lz4 <pool> zfs set copies=2 <pool> Setting a number of copies, is normally not useful for a multi-disk array, as the copies can end up on the same disk. But on a single disk, they are an insurance policy against bad sectors. Then you just zfs send your snapshots to it. I regularly use this as a local backup strategy with my work laptops. -- Scott Sullivan