RAID 5 - Not Active after Drive was removed

[mike29806]

Hi,

We have a QNAP TS-859U +, this is configured with RAID 5 using 8 2tb HDDs.

Drive 8 was flagged as unstable, an engineer went to site to remove the faulty drive to arrange a RMA but pulled out Drive 4 by mistake, the drive was immediately plugged back in but we lost connection to all the shares. The correct drive that was faulty was then removed and the QNAP was rebooted. The QNAP now states that the RAID5 is not active only giving one option which is to recover.

I have created ticket with QNAP, who provided some information but have yet to answer my question about the recovery option.

Any feedback from anyone who has had this before will be greatly appreciated.

Thanks
Micahel

[schumaku]

This is exactly what the RAID recovery is for - to recover the RAID from an accidentally removed HDD.

[mike29806]

I decided not to wait and ran the recovery, but as the unstable HDD was removed it states not enough disks to recover the RAID.

[schumaku]

Bring back the "unstable" drive and run recover...

[mike29806]

Just done that thanks, I am able to get into some shares but they only have a few files, I am just getting Loading Data, please wait when accessing Volume Management or RAID Management.
I guess at this point it is a waiting game...

[schumaku]

Get in touch with QNAP customer service please.

[mike29806]

I have received replacement drive which is now plugged in, it will not recover stating not enough Disks.

As disk 4 was removed by mistake surely there must be a telnet command that can be run to tell the system this drive is ok and has not failed so we can recover the RAID.

I have asked QANP for a support session tomorrow as they are +7 hours in front of me.

[mike29806]

All fixed without QNAP Support assistance being required. (unless you have a valid backup I would not recommend attempting this)

We had a valid backup of the data so we decided to fix ourselves.
Commands run are in bold

mdadm -E /dev/sda3
/dev/sda3:
Magic : a92b4efc
Version : 00.90.00
UUID : bd400d62:d7dfb889:635a4ce8:db92f33e
Creation Time : Thu Nov 17 11:36:01 2011
Raid Level : raid5
Used Dev Size : 1951945600 (1861.52 GiB 1998.79 GB)
Array Size : 13663619200 (13030.64 GiB 13991.55 GB)
Raid Devices : 8
Total Devices : 8
Preferred Minor : 0

Update Time : Thu Jul 3 03:11:15 2014
State : clean
Active Devices : 7
Working Devices : 8
Failed Devices : 1
Spare Devices : 1
Checksum : 97b7a240 - correct
Events : 0.30811273

Layout : left-symmetric
Chunk Size : 64K

Number Major Minor RaidDevice State
this 1 8 19 1 active sync /dev/sdb3

0 0 8 3 0 active sync /dev/sda3
1 1 8 19 1 active sync /dev/sdb3
2 2 8 35 2 active sync /dev/sdc3
3 3 0 0 3 faulty removed
4 4 8 67 4 active sync /dev/sde3
5 5 8 83 5 active sync /dev/sdf3
6 6 8 99 6 active sync /dev/sdg3
7 7 8 115 7 active sync /dev/sdh3 (New Drive replacing faulty drive )
8 8 8 51 8 spare /dev/sdd3 (Drive removed by mistake, being picked up as spare.)

[~] # mdadm --stop /dev/md0
mdadm: stopped /dev/md0

[~] # mdadm -CfR --assume-clean /dev/md0 -l 5 -n 8 /dev/sda3 /dev/sdb3 /dev/sdc3 /dev/sdd3 /dev/sde3 /dev/sdf3 /dev/sdg3 missing (We left out SDH3 as this was the new drive which had no data so we used the missing command)
mdadm: /dev/sda3 appears to contain an ext2fs file system
size=778717312K mtime=Wed Jul 2 16:01:22 2014
mdadm: /dev/sda3 appears to be part of a raid array:
level=raid5 devices=8 ctime=Thu Nov 17 11:36:01 2011
mdadm: /dev/sdb3 appears to be part of a raid array:
level=raid5 devices=8 ctime=Thu Nov 17 11:36:01 2011
mdadm: /dev/sdc3 appears to be part of a raid array:
level=raid5 devices=8 ctime=Thu Nov 17 11:36:01 2011
mdadm: /dev/sdd3 appears to be part of a raid array:
level=raid5 devices=8 ctime=Thu Nov 17 11:36:01 2011
mdadm: /dev/sde3 appears to be part of a raid array:
level=raid5 devices=8 ctime=Thu Nov 17 11:36:01 2011
mdadm: /dev/sdf3 appears to be part of a raid array:
level=raid5 devices=8 ctime=Thu Nov 17 11:36:01 2011
mdadm: /dev/sdg3 appears to be part of a raid array:
level=raid5 devices=8 ctime=Thu Nov 17 11:36:01 2011
mdadm: array /dev/md0 started.
[~] # mount /dev/md0 /share/MD0_DATA -t ext4 (final command to mount the RAID)

Signed into QNAP all data accounted for and the RAID is being rebuilt onto the new Drive.