Any known gotchas when upgrading 9.2.1 to 9.3.1?

[QS-IT]

We are currently running FreeNAS release 9.2.1 and want to take advantage of a few of the new features on 9.3.1, particularly the ability for FreeNAS to now automatically replace failed drives with spares.

Are there any known gotchas, or Best Practice guides, for upgrading from 9.2.1 to 9.3.1?

 

[Robert Trevellyan]

Best practice is to upgrade stepwise to the end of 9.2.1 (i.e. 9.2.1.9) before switching to 9.3. In all cases, backup the configuration before each update.

 

[clarknova]

Some hardware that runs 9.2 will not run 9.3 due to it moving to a GPT boot disk. You would be wise to try a clean install on your hardware before upgrading a running config.

More info here.
https://forums.freenas.org/index.php?threads/bios-gpt-puke.41631/

 

[Ericloewe]

If you're on 9.2.1.9, upgrades should be mostly painless.