Guys,
Just to comment with how I upgraded. I have a single pool: Data (5Tb consisting of 1Tb, 2Tb, and 3Tb mirrors). There is a subfilesystem under the pool Data/Users which is mounted on /Users. Data itself is mounted on /Volumes/Data as per OSX default. Having /Users mounted on ZFS meant that I had some extra steps in case the pool didn't come up after an install.
To upgrade:
1. Create a new admin user: Admin
As per above - my normal users are on ZFS, and it's nice to have a blank canvas in case.
2. Create a directory on my system SSD that isn't on ZFS /AdminHome
Avoiding ZFS.
3. Set Admin's home to be AdminHome
Avoiding ZFS.
4. Log out of my normal account and log in as Admin
When I logged in as Admin I checked for all processes still running as my normal user and killed them. Checked no process was hitting the ZFS pool, otherwise you can't export it. The export does an implicit unmount too.
5. sudo zpool export Data
Always export if you're planning on importing somewhere else.
6. Install Zevo
Best to upgrade drivers when they're not in use, hence export above.
7. Reboot
Woohoo.
8. Log in as admin to check everything worked
Best not to hit ZFS til I know it works.
9. mount Data/Users under /Users.
Not sure why it didn't automount. Data mounted automatically, Data/Users didn't. I didn't catch this the first time and when I logged in as my regular user I got the standard new users stuff.
10. Log in as my normal user.
Everything seems to be working. Zevo picked up my previous pool just fine. Dropbox sh*t it's pants, but it always does over tiny changes to filesystems and stuff. Otherwise, no issues.
I see Data/Users mounted on my desktop, as well as under /. The setting in the control panel isn't ticked, so not sure why it's there. That's purely cosmetic.
Otherwise, I'm happy. I'm planning on testing some more for a couple of days, and then upgrading the ZFS pool versions.
I hope upgrades go well for other users too.
Alex