kern/188328: UPDATING should provide caveats for running `zpool upgrade`

[Chris Nehren]

>Number:         188328
>Category:       kern
>Synopsis:       UPDATING should provide caveats for running `zpool upgrade`
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          doc-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Apr 06 21:20:00 UTC 2014
>Closed-Date:
>Last-Modified:
>Originator:     Chris Nehren
>Release:        10.0-STABLE
>Organization:
>Environment:
I can't `uname -a` because I can't boot the afflicted system. It's 10.0-STABLE after the new Delphix ZFS feature flags went in.
>Description:
Eager sysadmins like to upgrade their ZFS pool versions and then reboot. This can cause problems if one doesn't update the gpart bootcode. I presently have a workstation I can't boot because I didn't realize I needed to do this. Putting this information in UPDATING for every relevant feature flag change would save people like me rather a lot of time and frustration.
>How-To-Repeat:
Install 10-RELEASE with ZFS root. Upgrade to 10-STABLE after the new feature flags from Delphix went in. Reboot. Witness gptzfsboot being unable to import the bootpool.
>Fix:
A mailing list post (http://lists.freebsd.org/pipermail/freebsd-current/2014-January/047639.html) suggests upgrading the bootcode should be sufficient. This needs to get into UPDATING because foregoing this step leaves a system not bootable.

>Release-Note:
>Audit-Trail:
>Unformatted: