kern/124294: gmirror have inappropriate logic when working with bad hard-drive

[Denis Barov]

>Number:         124294
>Category:       kern
>Synopsis:       gmirror have inappropriate logic when working with bad hard-drive
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Jun 05 07:50:00 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Denis Barov
>Release:        FreeBSD 6,7,8
>Organization:
Yandex
>Environment:
FreeBSD sepulca.yandex.ru 6.3-STABLE FreeBSD 6.3-STABLE #5: Wed Feb 27 12:26:30 MSK 2008     root at sepulca.yandex.ru:/usr/obj/usr/RELENG_6/src/sys/SEPULCA  amd64
>Description:
For example, we have two gmirrored hard drives (da0 and da1). If first drive partially dead (have hardware errors) then,  during system boot, gmirror will insert it, and then try boot from it. In better case, boot fails. In worse case system will boot up and gmirror will try to sync second good disk with first bad. In this case data will be lost on both drives. I think it's serious trouble, because there's no way to get failover with any amount of disks. 
>How-To-Repeat:
Use gmirror with bad hard drive.
>Fix:
none

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