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
---
Talk Mailing List
talk@gtalug.org
https://gtalug.org/mailman/listinfo/talk