ReadyNAS Ultra 2: how to recover data from RAID-1 disks?

[divisionmd]

Hello,

- I have a ReadyNas -> Netgear RNDU2120-100PES (check image below).

- It has a "blue light" - but the network port NIC seems totally dead. Not link at all. So my guess unit works well but the NIC port has crashed.

- Its two disks in the drive two 2TB disks.

- My plan is this - and wanted to double check with support first before i do this:

Step 1) Complete > I have cloned one of the drive to a copy - so i am not working on the original drive.

Step 2) Complete >I have connected the cloned drive to PC / Linux Debian wheezy.

Step 3) Complete >I can see the device in fdisk however i cant mount it - it needs "mdadm" i understand.

Step 4) Not yet > I am about to do this: Install "mdadm" and "vgscan" and run:

# mdadm --assemble --scan
# vgscan
# vgchange -a y
# mount /dev/c/c /mnt

Since that is what i have found out that i should do in this forum.

Is this correct? Then i will proceed.

Any input/help is most welcomed - need to urgently recover data.

Best regards,

Johan

[StephenB]

You have an Ultra-2, not an RN102 - so your title isn't correct.

Your command sequence looks ok.

[mdgm-ntgr]

Fixed the thread title.

It's advisable to check disk health and the state of the RAID array before proceeding to run the commands you mentioned.

[divisionmd]

Hello mdgm,

- Can you update me on the commands i should run to check the "helath and state of RAID array" ?

- Also note - > i have one of the disks attached to a PC - should i attach both disk?

Best regards,
Johan

[divisionmd]

Hello Again,

- I know ran the commands:

# mdadm --assemble --scan
# vgscan
# vgchange -a y
# mount /dev/c/c /mnt

But cant seem to mount the drive- error "unknown filesystem type 'linux_raid_member". 

Note i have one of the two disks - connected to the PC.

Look at images below:

[mdgm-ntgr]

# mount -o ro -t ext4 /dev/c/c /mnt

[divisionmd]

Hello,

- Cant mount it > it says "is already mounted" ?

- Check attached image.

- Also tried to create a new folder /mnt/recovery - and mount it here instead of /mnt/sdb3 but no luck - seems something is preventing me from accessing this.

- Can you help me remotely? (ssh access)

[divisionmd]

Hello,

- Also this information is from dmesg:

[ 362.460636] md: md0 stopped.
[ 362.461213] md: bind<sdb1>
[ 362.469600] md: raid1 personality registered for level 1
[ 362.469881] md/raid1:md0: active with 1 out of 2 mirrors
[ 362.469904] md0: detected capacity change from 0 to 4293906432
[ 362.476292] md0: unknown partition table
[ 362.661170] md: bind<sdb2>
[ 362.662166] md/raid1:md1: active with 1 out of 2 mirrors
[ 362.662191] md1: detected capacity change from 0 to 536858624
[ 362.662521] md1: unknown partition table
[ 362.727698] md: bind<sdb3>
[ 362.818110] raid6: sse2x1 6145 MB/s
[ 362.886093] raid6: sse2x2 9477 MB/s
[ 362.954076] raid6: sse2x4 12507 MB/s
[ 362.954078] raid6: using algorithm sse2x4 (12507 MB/s)
[ 362.954080] raid6: using ssse3x2 recovery algorithm
[ 362.971233] async_tx: api initialized (async)
[ 362.971591] xor: automatically using best checksumming function:
[ 363.010060] avx : 25118.000 MB/sec
[ 363.329026] md: raid6 personality registered for level 6
[ 363.329028] md: raid5 personality registered for level 5
[ 363.329029] md: raid4 personality registered for level 4
[ 363.329260] md/raid:md2: device sdb3 operational as raid disk 0
[ 363.329411] md/raid:md2: allocated 0kB
[ 363.329423] md/raid:md2: raid level 5 active with 1 out of 2 devices, algorithm 2
[ 363.329424] RAID conf printout:
[ 363.329425] --- level:5 rd:2 wd:1
[ 363.329426] disk 0, o:1, dev:sdb3
[ 363.329452] md2: detected capacity change from 0 to 1995563728896
[ 363.329794] md2: unknown partition table
[ 586.406417] device-mapper: uevent: version 1.0.3
[ 586.406482] device-mapper: ioctl: 4.27.0-ioctl (2013-10-30) initialised: dm-devel@redhat.com
[ 6740.573943] EXT4-fs (md1): VFS: Can't find ext4 filesystem

[mdgm-ntgr]

Why are you trying to mount a partition from a disk? You're entering the wrong command

To mount the root volume you would mount /dev/md0

To mount the data volume you would mount /dev/c/c

[divisionmd]

Hello,

- Just dont get where the drive is mounted.

- The /dev/md0 > i can mount and looks ok - but no files here.

- The /dev/c/c does not exist? cant mount it - what am i doing wrong here.

- Want to mount the disk were the files are so i can restore them to remote destination.

Thanks for all help,

Best regards,

Johan

[divisionmd]

This might be a clue - its only mounting /dev/md0 not /dev/md1:

[ 363.329026] md: raid6 personality registered for level 6
[ 363.329028] md: raid5 personality registered for level 5
[ 363.329029] md: raid4 personality registered for level 4
[ 363.329260] md/raid:md2: device sdb3 operational as raid disk 0
[ 363.329411] md/raid:md2: allocated 0kB
[ 363.329423] md/raid:md2: raid level 5 active with 1 out of 2 devices, algorithm 2
[ 363.329424] RAID conf printout:
[ 363.329425] --- level:5 rd:2 wd:1
[ 363.329426] disk 0, o:1, dev:sdb3
[ 363.329452] md2: detected capacity change from 0 to 1995563728896
[ 363.329794] md2: unknown partition table
[ 586.406417] device-mapper: uevent: version 1.0.3
[ 586.406482] device-mapper: ioctl: 4.27.0-ioctl (2013-10-30) initialised: dm-devel@redhat.com
[ 6740.573943] EXT4-fs (md1): VFS: Can't find ext4 filesystem
[ 9510.301356] EXT4-fs (md0): INFO: recovery required on readonly filesystem
[ 9510.301361] EXT4-fs (md0): write access will be enabled during recovery
[ 9511.044098] EXT4-fs (md0): orphan cleanup on readonly fs
[ 9511.044167] EXT4-fs (md0): 1 orphan inode deleted
[ 9511.044169] EXT4-fs (md0): recovery complete
[ 9511.104265] EXT4-fs (md0): mounted filesystem with ordered data mode. Opts: (null)
[ 9607.929186] EXT4-fs (md0): mounted filesystem with ordered data mode. Opts: (null)
[ 9801.744210] EXT4-fs (md1): VFS: Can't find ext4 filesystem

- Maybe some additional commands are needed? so md1 can be monted (so /dev/c/c works)... ?

Best regards,
Johan

[divisionmd]

Hello,

- Maybe i need to run some "repair" commands? "fsck"?

- Maybe i need to run some other command?

- Maybe i need to mount/install both disks from the Netgear? so the Raid build correctly?

Please advice,

Thanks for help,

Best regards,

Johan