GEOM_MIRROR Errors

[Miroslav Lachman]

Nuno Martinho wrote:
>  
> I have a RAID 1 that was working fine without errors reported. The RAID was not on Degraded state.  
> When i shutdown Freenas, GEOM_MIRROR start to report errors during shutdown.  
> I’ve checked SMART and there are no problems with the disks.  
> 
> During shutdown:  
> Sep 10 07:33:15                kernel: ad6: TIMEOUT - WRITE_DMA48 retrying (1 retry left) LBA=976773167  
> Sep 10 07:33:20                kernel: ad6: TIMEOUT - WRITE_DMA48 retrying (0 retries left) LBA=976773167  
> Sep 10 07:33:25                kernel: ad6: FAILURE - WRITE_DMA48 timed out LBA=976773167  
> Sep 10 07:33:25                kernel: GEOM_MIRROR: Cannot write metadata on ad6 (device=raid1, error=5).  
> Sep 10 07:33:25                kernel: GEOM_MIRROR: Cannot update metadata on disk ad6 (error=5).  
> Sep 10 07:33:32                kernel: ad7: TIMEOUT - WRITE_DMA48 retrying (1 retry left) LBA=976773167  
> 
> 
> During startup:  
> Sep 10 07:47:47                kernel: ad6: 476940MB <WDC WD5000AAKB-00YSA0 12.01C02> at ata3-master UDMA100  
> Sep 10 07:47:47                kernel: ad7: 476940MB <WDC WD5000AAKB-00YSA0 12.01C02> at ata3-slave UDMA100  
> Sep 10 07:47:47                kernel: GEOM_MIRROR: Device raid1 created (id=3401427605).  
> Sep 10 07:47:47                kernel: GEOM_MIRROR: Device raid1: provider ad7 detected.  
> Sep 10 07:47:47                kernel: GEOM_MIRROR: Device raid1: provider ad6 detected.  
> Sep 10 07:47:47                kernel: GEOM_MIRROR: Component ad6 (device raid1) broken, skipping.  
> Sep 10 07:47:47                kernel: GEOM_MIRROR: Device raid1: provider ad7 activated.  
> Sep 10 07:47:47                kernel: GEOM_MIRROR: Device raid1: provider mirror/raid1 launched.  
> 
> If i try to insert disk “ad6” in the mirror:  
> Sep 10 07:49:40                kernel: GEOM_MIRROR: Component ad6 (device raid1) broken, skipping.  
> Sep 10 07:49:40                kernel: GEOM_MIRROR: Cannot add disk ad6 to raid1 (error=22).  
> 
> The only solution was rebuild the mirror.  
> 
> Why this errors?  

It can be caused by bad cables or controller. I had similar problems on 
ASUS RS-120 with Intel controller, somebody have same problems with 
Silicon Image chips.

You can re-use ad6 by:
gmirror forget raid1      [it will not destroy your mirror data, just 
remove info about disconnected devices (ad6 in this case)]
gmirror clear ad6         [remove metadata from ad6]
gmirror insert raid1 ad6  [reinsert ad6 in to raid1 and start resync]

Miroslav Lachman