ext4 errors on raid1, repair available?

Using TestDisk to repair the filesystem
Forum rules
When asking for technical support:
- Search for posts on the same topic before posting a new question.
- Give clear, specific information in the title of your post.
- Include as many details as you can, MOST POSTS WILL GET ONLY ONE OR TWO ANSWERS.
- Post a follow up with a "Thank you" or "This worked!"
- When you learn something, use that knowledge to HELP ANOTHER USER LATER.
Before posting, please read https://www.cgsecurity.org/testdisk.pdf
Posts: 2
Joined: 03 Feb 2013, 00:01

ext4 errors on raid1, repair available?

#1 Post by bbking »

Hi there,

I had a RAID1 system running under linux with ext4 but suddenly parts of the file system were only mounted read-only. OK, I thought lets run a fsck, which told me there are problems with some nodes. After rebooting suddenly grub told me it cannot find any filesystems and my system won't start any more.

I found testdisk and run it, but I am not sure what to do to run a recovery. I uploaded the log file (http://pastebin.com/HzrQf592) and made some screenshots. Any of you experts out there, could you take a look at it and tell me what chances I have to get my data back?

Thanks a lot in advance!

Screenshot1.png (89.67 KiB) Viewed 3159 times
Screenshot2.png (100.56 KiB) Viewed 3159 times
Screenshot3.png (45.71 KiB) Viewed 3159 times

Sponsored links

Posts: 2
Joined: 11 Feb 2013, 19:48

Re: ext4 errors on raid1, repair available?

#2 Post by raymor »

See the message "the hard disk seems to small".
It looks to me like testdisk is finding a filesystem larger than the disk, perhaps from when it was part of a RAID 0.
If you're 100% certain the files you are looking for are from a RAID1, not RAID0, try selecting a different partititon or having testdisk look for other filesystem superblocks.

User avatar
Site Admin
Posts: 5307
Joined: 18 Feb 2012, 15:08
Location: Le Perreux Sur Marne, France

Re: ext4 errors on raid1, repair available?

#3 Post by cgrenier »

Have you been able to list the files from the first partition listed, the ext4 filesystem starting at 0/32/33 ?

Posts: 2
Joined: 03 Feb 2013, 00:01

Re: ext4 errors on raid1, repair available?

#4 Post by bbking »

sorry for being that late with my answer!
cgrenier wrote:Have you been able to list the files from the first partition listed, the ext4 filesystem starting at 0/32/33 ?
No, I always get a wrong filesystem or bad superblock response, when I try to mount it .

Code: Select all

root@ubuntu:mdadm --assemble --scan -v
root@ubuntu:/home/ubuntu# cat /proc/mdstat 
Personalities : 
md2 : inactive sda1[1](S)
      970737600 blocks
unused devices: <none>

root@ubuntu:/home/ubuntu# mount /dev/md2 /mnt/
mount: /dev/md2: can't read superblock
Or how would you go for a file listing starting at 0/32/33 ?

Also, here is what dumpe2fs gives me when running on /dev/sda1

Code: Select all

root@ubuntu:/home/ubuntu# cat dumpe2fs.log|more
Filesystem volume name:   <none>
Last mounted on:          /
Filesystem UUID:          7f679719-9a0f-4879-8b52-a952ce05ee01
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      ext_attr resize_inode dir_index filetype extent flex_b
g sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Filesystem flags:         signed_directory_hash 
Default mount options:    (none)
Filesystem state:         not clean with errors
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              60678144
Block count:              242684400
Reserved block count:     12134220
Free blocks:              151646857
Free inodes:              60026972
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      966
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Flex block group size:    16
Filesystem created:       Thu Jan  6 15:40:50 2011
Last mount time:          Sat Jan 12 16:52:48 2013
Last write time:          Sat Jan 12 17:59:35 2013
Mount count:              3
Maximum mount count:      30
Last checked:             Wed Jan  9 21:10:32 2013
Check interval:           15552000 (6 months)
Next check after:         Mon Jul  8 21:10:32 2013
Lifetime writes:          966 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:	          256
Required extra isize:     28
Desired extra isize:      28
First orphan inode:       12853428
Default directory hash:   half_md4
Directory Hash Seed:      09a9f725-1e70-445e-85cc-c4b9579dfd8c
Journal backup:           inode blocks
FS Error count:           10
First error time:         Sat Jan 12 18:00:13 2013
First error function:     ext4_mb_release_inode_pa
First error line #:       3602
First error inode #:      0
First error block #:      0
Last error time:          Sat Jan 12 20:25:58 2013
Last error function:      ext4_remount
Last error line #:        4575
Last error inode #:       25034944
Last error block #:       0

Gruppe 0: (Blöcke 0-32767)
 Prüfsumme 0x0000 (0xcdac ERWARTET), ungenutzte Inodes 0
  Primary Superblock in 0, Gruppendeskriptoren in 1-58
  reservierte GDT Blöcke bei 59-1024
  Block bitmap in 2553887680 (bg #77938 + 15296), Inode Bitmap in 33554432 (bg #
1024 + 0)
...and this goes on till group 7406:

Code: Select all

Gruppe 7406: (Blöcke 242679808-242684399) [INODE_UNINIT, ITABLE_ZEROED]
 Prüfsumme 0x1f17, ungenutzte Inodes 8192
  Block bitmap in 242221070 (bg #7392 + 14), Inode Bitmap in 242221086 (bg #7392 + 30)
  Inode-Tabelle in 242228256-242228767 (bg #7392 + 7200)
  4592 freie Blöcke, 8192 freie Inodes, 0 Verzeichnisse, 8192 ungenutzte Inodes

dumpe2fs: /dev/sda1: Fehler beim Lesen von Bitmaps: Die Block-Bitmap kann nicht gelesen werden
thanks a lot in advance!