[Ocfs2-users] mounted.ocfs2 -f return Unknown: Bad magic number in inode

[Sunil Mushran]

Appears you formatted the devices before you partitioned them.
As the ocfs2 superblock is in the third block, it is not overwritten
during partition. This version of mounted.ocfs2 does not handle
this situation.

Easiest fix is hand editing the signature using a binary editor.

$ bvi -s 10240 /dev/sda

Change the ocfs2 signature (OCFSV2) to something else. Changing
one character is enough.

BOUTKHIL--CAPGEMINI--, Mohamed wrote:
> Hello,
>
> I have installed ocfs2 without problem and use it for a RAC10gR2.
> Only Clusterware files are ocfs2 type.
> multipath is also used.
> When I issue : mounted.ocfs2 -f
> I have a strange result:
>
> Device                FS     Nodes
> /dev/sda              ocfs2  Unknown: Bad magic number in inode
> /dev/sda1             ocfs2  pocrhel2, pocrhel1
> /dev/sdb              ocfs2  Not mounted
> /dev/sdf              ocfs2  Unknown: Bad magic number in inode
> /dev/sdf1             ocfs2  pocrhel2, pocrhel1
> /dev/sdg              ocfs2  Not mounted
> /dev/dm-0             ocfs2  Unknown: Bad magic number in inode
> /dev/dm-4             ocfs2  pocrhel2, pocrhel1
>
> Devices: sda and sdf  are different paths to the same LUN. dm-0 is the
> multipath as stated by the following command:
>  multipath -ll
> ASM_DISK_4 (360060e80056583000000658300004064) dm-3 HITACHI,OPEN-V
> [size=9.0G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:1:4 sde 8:64  [active][ready]
>  \_ 1:0:1:4 sdj 8:144 [active][ready]
> ASM_DISK_3 (360060e80056583000000658300004063) dm-2 HITACHI,OPEN-V
> [size=9.0G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:1:3 sdd 8:48  [active][ready]
>  \_ 1:0:1:3 sdi 8:128 [active][ready]
> ASM_DISK_2 (360060e80056583000000658300004062) dm-1 HITACHI,OPEN-V
> [size=9.0G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:1:2 sdc 8:32  [active][ready]
>  \_ 1:0:1:2 sdh 8:112 [active][ready]
> CRS_DISK (360060e80056583000000658300004060) dm-0 HITACHI,OPEN-V
> [size=9.0G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=2][active]
>  \_ 0:0:1:0 sda 8:0   [active][ready]
>  \_ 1:0:1:0 sdf 8:80  [active][ready]
>
> I have some questions:
> 1- The message "Unknown: Bad magic number in inode", what does it mean ?
> Can I discard it ?
> 2- sdb and sdg devices were an ocfs2 volume but not anymore. Why it is
> listed here ?
> 3- It seems there is a mismatch between dm-0 and dm-4. dm-0 must be the
> right one. dm-4 is an old multipath removed.. Is this info is reliable ?
>
> Does anyone can help me on this weird behavior?
>
> Thanks in advance,
>
>
> Mohamed.
>
>
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