Why: device ad0 disconnected

[Matjaz Kljun]

Hi everybody!

I set up gmirror and the whole system is running flawlessly for four 
months.
As  I remember back then everything was ok. The other day I tried to 
list gmirror
and saw that ad0 is disconnected. I followed Ralf's instructions 
(http://people.freebsd.org/~rse/mirror/)
while  setting up gmirror and later added lescur 
kern.geom.mirror.debug=2 in /boot/loader.conf.

Has anyone a suggestion what to do in my case? Thx for the answers.

This are some infos about the problem


# less /var/log/messages
       ...
       May 26 16:44:23 lescur kernel: ad0: 76351MB <SAMSUNG 
SP0802N/TK200-04> [155127/16/63] at ata0-master UDMA100
       May 26 16:44:23 lescur kernel: ad2: 76351MB <SAMSUNG 
SP0802N/TK200-04> [155127/16/63] at ata1-master UDMA100
       May 26 16:44:23 lescur kernel: GEOM_MIRROR: Device gm0 created 
(id=3442036432).
       May 26 16:44:23 lescur kernel: GEOM_MIRROR: Device gm0: provider 
ad0 detected.
       May 26 16:44:23 lescur kernel: GEOM_MIRROR: Device gm0: provider 
ad2 detected.
       May 26 16:44:23 lescur kernel: GEOM_MIRROR: Device gm0: provider 
ad2 activated.
       May 26 16:44:23 lescur kernel: GEOM_MIRROR: Device gm0: provider 
mirror/gm0 launched.
       May 26 16:44:23 lescur kernel: GEOM_MIRROR: Device gm0: 
rebuilding provider ad0.
       May 26 16:44:23 lescur kernel: GEOM_MIRROR: Device gm0: provider 
ad0 disconnected.
       May 26 16:44:23 lescur kernel: Mounting root from 
ufs:/dev/mirror/gm0s1a
       ...

# gmirror list
       Geom name: gm0
       State: DEGRADED
       Components: 2
       Balance: round-robin
       Slice: 4096
       Flags: NONE
       SyncID: 3
       ID: 3442036432
       Providers:
       1. Name: mirror/gm0
          Mediasize: 80060423680 (75G)
          Sectorsize: 512
          Mode: r5w5e2
       Consumers:
       1. Name: ad2
          Mediasize: 80060424192 (75G)
          Sectorsize: 512
          Mode: r5w5e3
          State: ACTIVE
          Priority: 0
          Flags: DIRTY
          SyncID: 3
          ID: 4083131479
             Geom name: gm0.sync

# mount
       /dev/mirror/gm0s1a on / (ufs, local, soft-updates)
       devfs on /dev (devfs, local)
       /dev/mirror/gm0s1f on /home (ufs, NFS exported, local, soft-updates)
       /dev/mirror/gm0s1e on /usr (ufs, local, soft-updates)
       /dev/mirror/gm0s1d on /var (ufs, local, soft-updates)