kern/113957: [gmirror] gmirror is intermittently reporting a degraded mirror array upon reboot.

[Kyle Lanclos]

The following reply was made to PR kern/113957; it has been noted by GNATS.

From: Kyle Lanclos <lanclos at ucolick.org>
To: bug-followup at FreeBSD.org
Cc:  
Subject: Re: kern/113957: [gmirror] gmirror is intermittently reporting a degraded mirror array upon reboot.
Date: Thu, 10 Jan 2008 16:55:06 -0800

 I see the same behavior on a Sun X2100 M2 system with two 250GB SATA
 drives. If I reboot the machine, it comes up with the first drive
 in the mirror (ad4) degraded, and commences a re-synch. The percentage
 varies somewhat, but it generally starts synch'ing at 0% complete.
 
 I am running FreeBSD 7.0-RC1, 32-bit.
 
 Similar to the behavior noted in the original submission, only the ad4
 device (the one used to 'seed' this gm0 mirror) comes up dirty on reboot.
 Unlike the original submission, I see this behavior every time I reboot,
 not 20% of the time.
 
 In each case, I reboot the machine by issuing the 'reboot' command,
 as opposed to yanking the power cord from the back of the server. The
 console messages at boot time indicate that all filesystems are clean.
 
 Here is the relevant section from dmesg:
 
 ad4: 238471MB <SEAGATE ST32500NSSUN250G 0741B59RT2 3AZQ> at ata2-master SATA300
 ad6: 238471MB <SEAGATE ST32500NSSUN250G 0741B59RQJ 3AZQ> at ata3-master SATA300
 SMP: AP CPU #1 Launched!
 GEOM_MIRROR: Device mirror/gm0 launched (1/2).
 GEOM_MIRROR: Device gm0: rebuilding provider ad4.
 Trying to mount root from ufs:/dev/mirror/gm0s1a
 
 Sample gmirror output:
 
 # gmirror status
       Name    Status  Components
 mirror/gm0  DEGRADED  ad4 (26%)
                       ad6
 
 # gmirror list
 Geom name: gm0
 State: DEGRADED
 Components: 2
 Balance: load
 Slice: 4096
 Flags: NONE
 GenID: 0
 SyncID: 1
 ID: 1395794316
 Providers:
 1. Name: mirror/gm0
    Mediasize: 250055999488 (233G)
    Sectorsize: 512
    Mode: r8w7e8
 Consumers:
 1. Name: ad4
    Mediasize: 250056000000 (233G)
    Sectorsize: 512
    Mode: r1w1e1
    State: SYNCHRONIZING
    Priority: 0
    Flags: DIRTY, SYNCHRONIZING
    GenID: 0
    SyncID: 1
    Synchronized: 26%
    ID: 1222153146
 2. Name: ad6
    Mediasize: 250056000000 (233G)
    Sectorsize: 512
    Mode: r1w1e1
    State: ACTIVE
    Priority: 0
    Flags: NONE
    GenID: 0
    SyncID: 1
    ID: 1772037181
 
 The mirror was established via the following set of operations:
 
 gmirror label -v -b load gm0 /dev/ad4
 
 echo geom_mirror_load=YES >> /boot/loader.conf
 
 # Revise all instances of /dev/ad4 to /dev/mirror/gm0 in /etc/fstab.
 
 reboot
 
 gmirror insert gm0 /dev/ad6
 
 Please let me know if there is any additional information I can provide.
 
 --Kyle