Weird problem with gmirror - cannot add the Good disk
when previously failed SATA disk is online
sonicy at otenet.gr
Mon May 18 10:28:12 UTC 2009
Achilleas Mantzios wrote:
> in advance sorry for the cross posting, it is just that freebsd-geom didnt seem that populated.
> I run 7.1-PRERELEASE, its a home server.
> today morning after a power failure, the rebuild my root gm0 failed on disk ad4.
> The messages were:
> May 18 08:02:02 panix kernel: ad4: WARNING - WRITE_DMA UDMA ICRC error (retrying request) LBA=268091264
> May 18 08:02:08 panix kernel: drm0: <Intel i865G GMCH> on vgapci0
> May 18 08:02:08 panix kernel: info: [drm] AGP at 0xf0000000 128MB
> May 18 08:02:08 panix kernel: info: [drm] Initialized i915 1.5.0 20060119
> May 18 08:02:08 panix kernel: drm0: [ITHREAD]
> May 18 08:02:08 panix kernel: ad4: FAILURE - device detached
> May 18 08:02:08 panix kernel: subdisk4: detached
> May 18 08:02:08 panix kernel: ad4: detached
> May 18 08:02:08 panix kernel: GEOM_MIRROR: Device gm0: provider ad4 disconnected.
> May 18 08:02:08 panix kernel: GEOM_MIRROR: Device gm0: rebuilding provider ad4 stopped.
It looks to me you got a bad disk now.
> I read http://www.eztiger.org/2008/08/removing-and-re-adding-a-disk-in-gmirror/
> hoping that the rebuld failure was temprary
> and so i tried to just run
> # gmirror forget gm0
> # gmirror insert gm0 ad4
> But the system responded (if i remember correctly)
> Unknown provider ad4.
> The system no longer could see ad4 being online.
> So i rebooted the system many times and had these results:
> -When having put offline ad4 (disconnected by hardware), the system booted ok.
> -When having both disks online the system responded consistently
> "GEOM_MIRROR: Cannot add disk ad6 to gm0 (error=22)."
> Which IMO is not very ok, since gm0 should add ad6 without problem,
> no matter if ad4 is online or not.
> -When having only ad4 online, then it simply cannot find gm0 at all. (kind of reasonable)
> So my only option is to have only ad6 online, with a current gmirror status:
> panix# gmirror status
> Name Status Components
> mirror/gm0 COMPLETE ad6
> Anyone has an idea of how should i proceed (besides buying a UPS unit!)
> Is it meaningfull to go for a new Disk to replace current ad4?
I'd recommend attaching the bad disk on its own to a system and perform
tests on it. Is the BIOS recognizing this properly? I would run hardware
tests on it - either manufacturer ones, or stuff like
sysutils/smartmontools. You could also try installing FreeBSD on it and
see if it works. And probably use dd to clean all the contents, esp.
the partition table and the last sector where geom information is stored.
> Why is the presence of the supposed bad disk ad4, affecting gm0,
> when having already told gm0 to forget about ad4?
The bad disk may be sending confusing signals to the bus / IDE
interface. I've had this once (although it was due to a bad cable). The
entire mirror would disappear suddenly.
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