[Ocfs2-users] Partition table crash, where can I find debug message?

[Sunil Mushran]

Hard to say. You'll need to investigate the extent of the crash.

On 10/12/2011 10:49 AM, Frank Zhang wrote:
>
> Sorry, it's not power outage, it's just a normal reboot.
>
> Is this serious to corrupt the super block?
>
> *From:*Frank Zhang
> *Sent:* Wednesday, October 12, 2011 10:37 AM
> *To:* 'Sunil Mushran'
> *Cc:* 'ocfs2-users at oss.oracle.com'
> *Subject:* RE: [Ocfs2-users] Partition table crash, where can I find debug message?
>
> Thanks Suni. Yes the terminology should be super block corruption.
>
> I checked with my colleague they said  the ISCSI server suffered a power outage yesterday so they rebooted it.
>
> Given it was under heavy usage because of many VM running on, I guess this may be the cause. now I am trying to recover it
>
> *From:*Sunil Mushran [mailto:sunil.mushran at oracle.com] <mailto:[mailto:sunil.mushran at oracle.com]>
> *Sent:* Wednesday, October 12, 2011 10:08 AM
> *To:* Frank Zhang
> *Cc:* 'ocfs2-users at oss.oracle.com'
> *Subject:* Re: [Ocfs2-users] Partition table crash, where can I find debug message?
>
> Not sure what you mean by a partition table crash. Is it that someone
> overwrote the partition table on the iscsi server? That's what it looks
> like. If mount cannot detect the fs type, then it means atleast superblock
> corruption. And such corruptions typically caused by external entities.
> Stray dd perhaps.
>
> Did you try recovering the superblock using one of the the backups?
> fsck.ocfs2 -r [1-6] /dev/sdX ?
>
> On 10/11/2011 07:04 PM, Frank Zhang wrote:
>
> Hi Experts, recently I observed a partition table crash that made me really scared.
>
> I have two OVM servers sharing OCFS2 over iscsi, after running  a bunch of VMs for a while,  all VMs were gone and I saw the mount points of OCFS2 gone on both hosts.
>
> Then I tried to mount it again, the iscsi device crashed by saying "please specify filesystem type". I checked dmesg but there is nothing useful except
>
> "SCSI device sdc: drive cache: write back
>
> sdc: unknown partition table
>
> sd 2:0:0:1: Attached scsi disk sdc
>
> sd 2:0:0:1: Attached scsi generic sg3 type 0
>
> OCFS2 Node Manager 1.4.4
>
> OCFS2 DLM 1.4.4
>
> OCFS2 DLMFS 1.4.4
>
> OCFS2 User DLM kernel interface loaded
>
> connection1:0: detected conn error (1011)"
>
> basically after logging into ISCSI device on both hosts, I created soft links of /dev/ovm_iscsi1 pointing to device node under /dev/disk/by-path/real_isci_device, then I formatted /dev/ovm_iscsi1 to OCFS2 and mounted them to somewhere(of course I configured /etc/ocfs2/cluster.conf and made o2cb correctly start).
>
> Could somebody tell me where to get more debug info to trace the problem? This is really scared considering I may lose all my VMs because of the silent crash.
>
> And is there any way to recover the partition table? Thanks
>
>   
>   
> _______________________________________________
> Ocfs2-users mailing list
> Ocfs2-users at oss.oracle.com  <mailto:Ocfs2-users at oss.oracle.com>
> http://oss.oracle.com/mailman/listinfo/ocfs2-users
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://oss.oracle.com/pipermail/ocfs2-users/attachments/20111012/de661056/attachment.html