Re: Data recovery from linear array (Intel SS4000-E)
From: Phil Turmel <hidden>
Date: 2011-10-16 18:46:46
On 10/16/2011 11:49 AM, Johannes Moos wrote:
Hi Phil, I recreated the Array and it started.quoted
As you can see, the partition table corresponds to the size of the combined devices. Metadata type 0.90 is at the end of each member, so the first sector of loop0 will become the first sector of md0.Right, /dev/md0 now looks exactly the same as /dev/loop0: root@ThinkPad /media/Backup/NAS # fdisk -l /dev/md0 Disk /dev/md0: 1638.7 GB, 1638744850432 bytes 255 heads, 63 sectors/track, 199232 cylinders, total 3200673536 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/md0p1 1 16064 8032 77 Unknown /dev/md0p2 16065 3200673535 1600328735+ 88 Linux plaintextquoted
quoted
From what I read in a forum it's possible to mount the XFS partition with an offset, in my case that would be 00ae0000 (last line in hexdump).Shouldn't be necessary. I expect your LV w/ XFS to show up properly.Nothing happened, so I tried as described in the forum post I mentioned (about a pretty much identical NAS and so LVM):
Hmmm. pvs should have shown it.
quoted hunk ↗ jump to hunk
root@ThinkPad /media/Backup/NAS # hexdump -C /dev/md0 | head -n 150 | grep XFSB 00ae0000 58 46 53 42 00 00 10 00 00 00 00 00 00 04 00 00 |XFSB............| Offset for XFS-Partition is 00ae0000, that's 11403264 in decimal, so I tried (read only): root@ThinkPad /media/Backup/NAS # losetup -r -o 11403264 /dev/loop4 /dev/md0 and then I got: root@ThinkPad /media/Backup/NAS # disktype /dev/loop4--- /dev/loop4Block device, size 1.490 TiB (1638733447168 bytes) XFS file system, version 4 Volume name "" UUID 705BF11E-8F69-1CDA-8727-00004868BBE3 (DCE, v1) Volume size 1 GiB (1073741824 bytes, 262144 blocks of 4 KiB) Small progress, but volume size only 1 GiB? I didn't ran xfs_check or xfs_repair so far because there's probably a better way to do it :)
I'm a bit weak on XFS. Anyone else care to comment? Phil