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After this (Iomega Home Media disk corruption - data recovery help asked) problem solved... i have a new one..

I'm trying to understand why my Iomega Home Media Stopped working, and need for that to see what happened on the OS Logical Volume. For reading purpose, i will remind having a Seagate 1TO hard drive mounted /dev/sdc, running GPT, Soft Raid (on one disc : Wonder why raid ?), with LVM2 Volume groups that has a 4GB partition, a 16GB OS Partition (i need to access) and a 921GB i have managed to gain access to...

Attacking the os partition, i tried an ubuntu automount that ended with this error

Error mounting /dev/dm-1 at /media/ubuntu/6b08ba57-d9c9-46bc-af28-e57b222bad6d: Command-line `mount -t "xfs" -o "uhelper=udisks2,nodev,nosuid" 
"/dev/dm-1" "/media/ubuntu/6b08ba57-d9c9-46bc-af28-e57b222bad6d"' exited with non-zero exit status 32: 
mount: /dev/mapper/md0_vg-vol1: can't read superblock

Googling this error leads to make an File System Check which can be done only with xfs_check / xfs_repair. But problems continue here as none of these two commands work :

ubuntu@ubuntu:/$ sudo xfs_check /dev/md0_vg/vol1 
xfs_check: read failed: Input/output error
xfs_check: cannot init perag data (5)
xfs_check: read failed: Input/output error
XFS: failed to find log head
ERROR: cannot find log head/tail, run xfs_repair

ubuntu@ubuntu:/$ sudo xfs_repair /dev/md0_vg/vol1 
Phase 1 - find and verify superblock...
superblock read failed, offset 4293918720, size 131072, ag 1, rval -1

fatal error -- Input/output error

What can i do to solve this and recover data on this OS partition, or even better restore partition to an active state... Is the hard disk failing ?

EDIT : To complete informations, here is the mtab :

root@ubuntu:/home/ubuntu# cat /etc/mtab
/cow / overlayfs rw 0 0
proc /proc proc rw,noexec,nosuid,nodev 0 0
sysfs /sys sysfs rw,noexec,nosuid,nodev 0 0
udev /dev devtmpfs rw,mode=0755 0 0
devpts /dev/pts devpts rw,noexec,nosuid,gid=5,mode=0620 0 0
tmpfs /run tmpfs rw,noexec,nosuid,size=10%,mode=0755 0 0
/dev/sdd1 /cdrom vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro 0 0
/dev/loop0 /rofs squashfs ro,noatime 0 0
none /sys/fs/cgroup tmpfs rw 0 0
none /sys/fs/fuse/connections fusectl rw 0 0
none /sys/kernel/debug debugfs rw 0 0
none /sys/kernel/security securityfs rw 0 0
tmpfs /tmp tmpfs rw,nosuid,nodev 0 0
none /run/lock tmpfs rw,noexec,nosuid,nodev,size=5242880 0 0
none /run/shm tmpfs rw,nosuid,nodev 0 0
none /run/user tmpfs rw,noexec,nosuid,nodev,size=104857600,mode=0755 0 0
none /sys/fs/pstore pstore rw 0 0
systemd /sys/fs/cgroup/systemd cgroup rw,noexec,nosuid,nodev,none,name=systemd 0 0
gvfsd-fuse /run/user/999/gvfs fuse.gvfsd-fuse rw,nosuid,nodev,user=ubuntu 0 0
/dev/sda2 /media/ubuntu/70E04BA9E04B73FE fuseblk rw,nosuid,nodev,allow_other,default_permissions,blksize=4096 0 0
/dev/mapper/7ebf5eba_vg-lv28ab8112 /media/ubuntu/594eab64-3663-4ace-bbb0-aebe31772a0d xfs rw,nosuid,nodev,uhelper=udisks2 0 0
/dev/sda1 /media/ubuntu/78AE5DC4AE5D7B96 fuseblk rw,nosuid,nodev,allow_other,default_permissions,blksize=4096 0 0
/dev/sdb1 /media/ubuntu/7EA4E8DBA4E896C5 fuseblk rw,nosuid,nodev,allow_other,default_permissions,blksize=4096 0 0
/dev/loop1 /media/ubuntu/f24d667d-d64f-6540-b023-4f1d53e8c97c ext2 rw,nosuid,nodev,uhelper=udisks2 0 0
/dev/mapper/md0_vg-BFDlv /media/ubuntu/b54e7759-4a09-4514-bc1d-f0dbd8570896 ext2 rw,nosuid,nodev,uhelper=udisks2 0 0

Hope it help understanding problem ...

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2 Answers 2

Is it possible that this lv is not of the xfs type ? (if it's for an operating system, maybe it more likely to be ext3 or ext4).

could you try file -s /dev/md0_vg/vol1 ?

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here is the result of the command : root@ubuntu:/home/ubuntu# file -s /dev/md0_vg/vol1 /dev/md0_vg/vol1: symbolic link to '../dm-2' –  tdldp Dec 5 '13 at 19:19
@tdldp then what prints ˋfile -s /dev/dm-2ˋ –  Emmanuel Dec 5 '13 at 20:51

Emmanuel sorry for late answer to your demand : Here is the result :

root@ubuntu:/dev# file -s /dev/dm-2 /dev/dm-2: SGI XFS filesystem data (blksz 4096, inosz 256, v2 dirs)

It is a XFS filesystem as it declares, but cannot get in it and get files back... Is the harddrive failing ?

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To identify block device types, one would usually use blkid instead of file -s. –  David Foerster Oct 3 '14 at 15:52

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