This question is related to this question: Not enough components to start the RAID array?

I'm trying to retrieve data from a "Western Digital MyBook World Edition (white light)" NAS device. This is basically an embedded Linux box with a 1TB HDD in it formatted in ext3. It stopped booting one day for no apparent reason.

I have extracted the HDD from the NAS device and installed it in a desktop machine running Ubuntu 10.10 in the hope of accessing the files on the drive. I have followed instructions in this forum post, intended to mount the drive through Terminal: http://mybookworld.wikidot.com/forum/t-90514/how-to-recover-data-from-wd-my-book-world-edition-nas-device#post-976452

I have identified the partition that I want to mount and recover files from as /dev/sd4 by running "fdisk -l" and getting this:

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0001cf00

Device Boot Start End Blocks Id System
/dev/sdb1 5 248 1959930 fd Linux raid autodetect
/dev/sdb2 249 280 257040 fd Linux raid autodetect
/dev/sdb3 281 403 987997+ fd Linux raid autodetect
/dev/sdb4 404 121601 973522935 fd Linux raid autodetect//

When I try to mount using: "mount -t ext3 /dev/sdb4 /media/xyz" I get the following error:

mount: wrong fs type, bad option, bad superblock on /dev/sdb4,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so

And "dmesg | tail" shows me:

[ 15.184757] [drm] Initialized nouveau 0.0.16 20090420 for 0000:01:00.0 on minor 0
[ 15.986859] [drm] nouveau 0000:01:00.0: Allocating FIFO number 1
[ 15.988379] [drm] nouveau 0000:01:00.0: nouveau_channel_alloc: initialised FIFO 1
[ 16.353379] EXT4-fs (sda5): re-mounted. Opts: errors=remount-ro,commit=0
[ 16.705944] tg3 0000:02:00.0: eth0: Link is up at 100 Mbps, full duplex
[ 16.705951] tg3 0000:02:00.0: eth0: Flow control is off for TX and off for RX
[ 16.706102] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 19.125673] EXT4-fs (sda5): re-mounted. Opts: errors=remount-ro,commit=0
[ 27.600012] eth0: no IPv6 routers present
[ 373.478031] EXT3-fs (sdb4): error: can't find ext3 filesystem on dev sdb4.

I guess that last line is the punch line :)

Why can't it find the ext3 filesystem on my drive? What do I need to do to mount this partition and copy its contents? Does it have anything to do with the drive being part of a RAID Array (see question mentioned above)?

Many thanks to any who can help.

  • Is there a reason you are posting the same question again instead of following up in your first one? You seem to have gotten the answer there: you need to use mdadm to activate the arrays. You also might try running sudo blkid and see what it finds on the drive. It may not be using ext3.
    – psusi
    Commented Jan 17, 2011 at 18:53
  • I was wondering what did you end up doing with this problem? mount: wrong fs type, bad option, bad superblock on /dev/sdb4, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so I'm here too and I don't know where to go from here... I would love to hear your comments.
    – user25378
    Commented Sep 21, 2011 at 18:23

3 Answers 3


Sounds like the file system got corrupted somehow.

You can try "fsck -t ext3 /dev/sdb4" and see if that fixes your issues.

Also, make certain that ext3 is the correct file system, if I understand right fsck can corrupt data if you give it the wrong file system.


Indeed the issue has been resolved by an answer from @Oli to another similar question that I posted here: Not enough components to start the RAID array?

The HDD was set up as having 4 partitions of RAID-1. This is probably why it could not be mounted. Having installed mdadm and having used it to "assemble" the drive I was able to see mount it via Disk Utility.

See the answer to my other question above for full details.

  • 1
    Why on EARTH would the drive have multiple partitions setup in RAID-1 together? That makes literally no sense at all. RAID-1 is to protect in case of a drive failure. If the drive fails, you lose all partitions in a worst-case scenario. Perhaps it's to help in case corruption only occurs in one of the partition's blocks? Commented Feb 9, 2012 at 15:31
  • I don't know why the drive was partitioned this way. All I can say is that I took it out of a defunct "Western Digital My Book" NAS drive.
    – urig
    Commented Jul 28, 2014 at 14:24

I recently had an issue with my Western Digital My Book World Edition White light 2TB NAS (only 1 HD). It was working perfectly for a very long time when I moved and thought hey, why don't I set my stuff up right and put a static IP on this thing so all my computers can map to it everytime instead of having to discover it each time and see what DHCP IP was given. So I did that, and it worked. Then while I was in the configuration of the NAS, I saw that a system update was available. Dumb a$$ me decided to go ahead and get the latest update as that is supposed to be a good thing right? It is all automated and you can't really do anything except click the button, but after it did it's thing, my NAS was a brick. The bottom white light would stay lit for an extremely long period of time and then fade out and back. No luck getting it on the LAN either. Resets, reboots, prayers, user manuals; didn't help. Some research later, turns out I am not the only idiot who messed with a good thing and paid the price. The drive was still spinning so I had the joy of getting it out of the case. I could probably put it back together if I wanted to, but after this little experience with EXT3 and XFS file systems, I think I will be better off just shoving it into a bay on my Windows 7 box and farming it out (NTFS) from there. Not like 2TB is all that impressive in NAS size anymore anyway.

Now that story time is over, here is what I found when trying to get the files off via an External USB enclosure connected to my Windows 7 Desktop: the drive has four partitions. Two of them are EXT3 and with a little messing around and a good application (EXT2FSD), I was able to read the two EXT3 file systems in Windows natively. I found the folders where my files should be but to my dismay, nothing is in them. Turns out, the fourth partition is where the good stuff is and it is setup as an XFS file system. It showed up as Raw though.

This is not easy to see in Windows. Raise Data Recovery offers paid software that can save your bacon or at least give you a glimmer of hope as you can try it free and at least see that your files are actually still there. Mine were not deleted or anything so my file structure is perfect. If you are looking for deleted files, it will do it as long as they have not been written over, but the menu tree may be a bit cryptic to go through. My files are still there and waiting for me in perfect form, but I am going to take my drive to a friends house who loves linux and see if Mint (it says it can see XFS) can see the data without forking over around 28 USD for the Raise software. Especially in my case where I am not trying to recover deleted files. I just need to read the damn partition cause my NAS went t!ts up during a firmware update (thanks again Western Digital). At least I still have a working 2TB Western Digital Green drive to shove in my computer when I get done pulling my files off and reformatting.

Hope this is not too late for you.

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