16.04 to 18.04 upgrade with ZFS

**wintermute000** · December 16th, 2018

I'm running 16.04 ATM on my home server, and I wish to upgrade to 18.04. The main concern I have is ZFS.

Has anyone done this upgrade with ZFS? Any hints/tips?

I can lose everything on the server except for ZFS. Well technically I can lose that as well since I do have backups, however, many TB of data will take literally days to copy over again, and will be tedious in the extreme.

FWIW I'm using the HWE stack.

**howefield** · December 16th, 2018

Thread moved to the "Server Platforms" forum for a better fit.

**Tadaen_Sylvermane** · December 16th, 2018

I've never had data loss on an upgrade. That being said, as long as you used the official Ubuntu packages, and not custom self compiled stuff there should be no problem with the upgrade. ZFS is just a filesystem. It doesn't have special requirements for upgrading as far as I know, maybe if you have root on zfs then. Not sure about that.

*EDIT* Unless you have a compelling reason not to, I'd suggest sticking with 16.04 for now. 16.04 is still supported for another 2.5 years give or take. The longer you let 18.04 mature, the more reliable the upgrade process will likely be I'd guess. Ubuntu isn't known for clean upgrades. I know I don't plan on pushing for my 18.04 upgrade until 20.04 is about to be released. Got about a year and a half for that.

**wintermute000** · December 17th, 2018

point taken. Everything (except for a bit of lab stuff) is apt-get or pip installed so I'm hoping its oK, but yes why do it now I suppose.
My ZFS pool is on separate disks to my / so yeah should be able to fix it, even with a live CD or complete OS re-install. UNless something in the upgrade sledgehammers it I supose.

**de0xyrib0se** · December 18th, 2018

You can't lose everything unless you delete everything.

Upgrade is seamless, leaving the underlying filesystems untouched, just replaces binary code.

If you are that paranoid about your pools (which are separate form your root partition) you can always export them, perform the upgrade and then re-import them, takes 10 seconds.

**zorlax** · December 27th, 2018

You already have your answers but one of the beautiful things about ZFS is the ability to move pools. If you're pool is on separate disks you should be good. If you want to do a belt and suspenders upgrade export the pool and disconnect the disks before fiddling with the OS.