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Forum Discussion
Access ReadyNAS RNDU2000 mirrored drive directly from Linux.
Also posted in Ubuntu Forum (http://ubuntuforums.org/showthread.php?t=2272848)
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Drive is one from a mirrored pair out of a ReadyNAS RNDU2000 (2 drive unit). I assume this drive uses 16K file system block size.
I have it attached via a USB<->SATA adapter. (tableau write blocker)
Fdisk sees the device as /dev/sdb1 (GPT)
# file -sL /dev/sdb1
/dev/sdb1:Linux Software Raid version 1.2 (1) UUID=d0...b0 name=A0...3A:0 level=1 disks=2
Attempted to reassemble from one drive (force assemble with only one member with --run):
# mdadm --assemble --run /dev/md0 /dev/sdb1
mdadm: cannot re-read metadata from /dev/sdb1 - aborting
Attempted normal mount:
# mount -o ro /dev/sdb1 /mnt/drive
mount: unknown filesystem type 'linux_raid_member'
Attempted to fuse mount drive:
# mkdir /mnt/drive
# fuseext2 -o ro,allow_other /dev/sdb1 /mnt/drive
... Probe failed [main (fuse-ext2.c:347)]
Tried to scan for volume groups:
# vgscan
...
No volume groups found
I'm using Ubuntu 14.04LTS
fuse-ext2 version '0.4', fuse_version:'29'
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I have also tried the Ubuntu9.10 VMware image referred to in these forums (http://www.readynas.com/forum/viewtopic.php?f=11&t=35153&start=105#p275675)
without any success.
The drive (both drives) is working in the ReadyNAS unit but that is not my issue!
Any ideas how I can mount and access this drive from Linux?
----------------------------------------------
Drive is one from a mirrored pair out of a ReadyNAS RNDU2000 (2 drive unit). I assume this drive uses 16K file system block size.
I have it attached via a USB<->SATA adapter. (tableau write blocker)
Fdisk sees the device as /dev/sdb1 (GPT)
# file -sL /dev/sdb1
/dev/sdb1:Linux Software Raid version 1.2 (1) UUID=d0...b0 name=A0...3A:0 level=1 disks=2
Attempted to reassemble from one drive (force assemble with only one member with --run):
# mdadm --assemble --run /dev/md0 /dev/sdb1
mdadm: cannot re-read metadata from /dev/sdb1 - aborting
Attempted normal mount:
# mount -o ro /dev/sdb1 /mnt/drive
mount: unknown filesystem type 'linux_raid_member'
Attempted to fuse mount drive:
# mkdir /mnt/drive
# fuseext2 -o ro,allow_other /dev/sdb1 /mnt/drive
... Probe failed [main (fuse-ext2.c:347)]
Tried to scan for volume groups:
# vgscan
...
No volume groups found
I'm using Ubuntu 14.04LTS
fuse-ext2 version '0.4', fuse_version:'29'
-------------------------------------------------------------
I have also tried the Ubuntu9.10 VMware image referred to in these forums (http://www.readynas.com/forum/viewtopic.php?f=11&t=35153&start=105#p275675)
without any success.
The drive (both drives) is working in the ReadyNAS unit but that is not my issue!
Any ideas how I can mount and access this drive from Linux?
10 Replies
Replies have been turned off for this discussion
- The RNDU2000 is the Ultra 2, for which the procedure to attempt to recover data using Linux is different to that used for Sparc ReadyNAS.
For the Ultra 2 you could do e.g.
# mdadm --assemble --scan
# vgscan
# vgchange -a y
# mount -o ro /dev/c/c/ /mnt/drive
Note the steps above do not include checking disk health, the RAID superblock etc. which would be advisable if you don't know what state the array is in. - Thanks for the reply:
#mdadm --assemble --scan
mdadm: cannot re-read metadata from /dev/sdb3 - aborting
mdadm: cannot re-read metadata from /dev/sdb2 - aborting
mdadm: cannot re-read metadata from /dev/sdb1 - aborting
mdadm: No arrays found in config file or automatically
I tried this on both drives!
I must mention at this point the drive is write blocked (read only). - Well the array is clearly not in a good state then.
I assume you have no backup?
Have you checked the health of the disks?
There must be a reason the disks have gone read-only. - No the contrary, the array is in a perfect state. This is an exercise to access a perfectly working array from Linux.
Once I figure the correct commands for a known working array I will move onto faulty arrays. - Perhaps try a different adapter to connect the disk to your PC?
mdgm wrote: Well the array is clearly not in a good state then.
I assume you have no backup?
Have you checked the health of the disks?
There must be a reason the disks have gone read-only.
I apologize and you may after all be right. I wasn't paying close enough attention to the output of file -sL and I have found something weird in the setup.
There are 3 partitions on each disk.
file -sL reports /dev/sdb1 is level=1 disks=2
file -sL reports /dev/sdb2 is level=1 disks=2
file -sL reports /dev/sdb3 is level=5 disks=2
Level 5? I didn't think the ULTRA 2000 (2 disk unit) supported level 5.
I must have broken it somehow which is unlikely as I tested the USB<->SATA write blocker.
So to find out if it is actually still working I am going to plug the drives back into the NAS unit and fire it up!!!- Plug the drives back into the ULTRA 2 and it starts up fine and I can access all the shares.
Back to square one!!!
So how can I access these drives (with the weird RAID 5 setup) from Linux? - It uses that "weird RAID 5 setup" to enable expansion from 2 disks to 3 in systems that support that.
It sounds like you should try a different USB to SATA adapter or better yet connect the disks to internal SATA ports and boot off a Linux Live CD - Many older USB2 adapters don't support drives > 2 TB.
StephenB wrote: Many older USB2 adapters don't support drives > 2 TB.
Some don't!
But this one has been tested (by me) up to 4TB.
And the two drives in question are only 1.5TB anyway!!!
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