misc/160591: Boot on zfs root with degraded raidz2

[Ighor Poteryakhin]

>Number:         160591
>Category:       misc
>Synopsis:       Boot on zfs root with degraded raidz2
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Sep 09 16:00:23 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Ighor Poteryakhin
>Release:        8.2-STABLE
>Organization:
>Environment:
FreeBSD real-big-one.office.furgon-center.ru 8.2-STABLE FreeBSD 8.2-STABLE #0: Fri Sep  2 11:02:24 MSD 2011     ighor at real-big-one.office.furgon-center.ru:/usr/obj/usr/src/sys/CUSTOM  amd64

>Description:
System was updated to 8.2-STABLE from 8.2-RELEASE and has ZFS RAIDZ2 with 6 hdds (500Gb each). Total capacity was (6-2)*500, approx 2T. Each hdd is conencted to one the same ICH10 controller, visible to BIOS and works stable. When one(any) HDD is removed system fails to boot from degraded ZFS RAIDZ2.
>How-To-Repeat:
Remove one of 6 HDDs from RAIDZ2 on 8.2-STABLE - system will not boot from degraded RAIDZ2.
>Fix:
8.2-RELEASE works fine

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