GEOM_MIRROR GPT table corrupt or invalid

[Johan Hendriks]

peter harrison schreef:
>
>
> On 27 September 2011 22:58, Johan Hendriks <joh.hendriks at gmail.com 
> <mailto:joh.hendriks at gmail.com>> wrote:
>
>     peter harrison schreef:
>
>         Hello list,
>
>         I have a problem with a software RAID1. This was created under
>         Freenas 0.7.2
>         (using the web interface - FreeBSD 7.3 under the hood) which
>         as I understand
>         it uses GPT and GEOM_MIRROR. This Freenas is running on AMD64
>         on an ESXi 4.1
>         host with the 2 drives for the mirror passed through as raw
>         disks to the
>         Freenas guest - if that makes a difference.
>
>         This mirror now fails to mount on boot. Checking the boot
>         messages I see
>         this straight after the drives are detected:
>
>         GEOM: da1: the secondary GPT table is corrupt or invalid.
>         GEOM: da1: using the primary only -- recovery suggested
>
>         Further on I see:
>
>         GEOM_MIRROR: Force device data start due to timeout
>         GEOM_MIRROR: Device mirror/data launched (1/2)
>
>         The mirror is not mounted when booting is completed - no
>         further messages
>         during boot - mount says:
>
>         freenas:~# mount
>         /dev/da0s1a on / (ufs, local, soft-updates)
>         devfs on /dev (devfs, local)
>         procfs on /proc (procfs, local)
>
>         When I try to mount it manually I get a continually scrolling
>         g_vfs error:
>
>         g_vfs_done():mirror/datap1[READ(offset=-636932692096956416,
>         length =16384)]
>         error = 5
>
>         and the guest becomes unresponsive.
>
>         GEOM isn't something I'm really familiar with - so any insight
>         on how this
>         happened would be interesting. But the main question is, is
>         there anyway of
>         getting the data off this disk? (I have some backups, but
>         they're not
>         complete).
>
>         Thanks for any help.
>
>
>
>         Peter Harrison.
>
>     You can not use gmirror and GPT at the same time on the whole disk.
>
>     Both use the same diskspace to write there meta data.
>     What you can do is to mirror the partitions seperately.
>     A nice howto you can find here
>     http://www.unix-heaven.org/node/20
>
>
>
> Thanks Johan, I'll check the link out. This mirror has been running OK 
> for the last 6 months - so perhaps I misunderstood how FreeNAS set it 
> up in the first place?
>
>
>     You can recover the GPT, but then the mirror can not load.
>     if you recreate the mirror after that, the gpt label gets corrupt.
>
>
> No hope of being able to recover any data then?
>
> Thanks again,
>
>
>
> Peter Harrison.
>
>
>
>     regards,
>     Johan
>
>
I had the same issue, i saw the message of the gpt label, but it just 
booted.
So i never looked at it in detail.
Until i upgraded to 8.2, then it does not boot anymore.
8.2 just did not boot with a corrupted GPT label.
If you repair the label, you can edit the fstab file to use the normal 
filesystems and not the mirrored one.

Then it boot of just one disk, then create the mirrors of the slices as 
stated by the webpage.

If you are not sure, disconnect the second drive before doing anything.
It should be accesable in case things really did go wrong through a live 
cd or something.

So make sure you can boot of a single disk and work on from there.

regards,
Johan