Hello,
first of all: I am new to mailinglists but i hope my way to ask here is correct.
I am having trouble getting my Raid 5 assembled again after i manually
removed one disk.
So here is what what it looked like at the time it was working:
mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Wed Jan 7 18:14:37 2015
Raid Level : raid5
Array Size : 5860270080 (5588.79 GiB 6000.92 GB)
Used Dev Size : 2930135040 (2794.39 GiB 3000.46 GB)
Raid Devices : 3
Total Devices : 4
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Tue Aug 30 21:49:51 2016
State : clean
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Name : NAS:0 (local to host NAS)
UUID : 7b0eee59:07f87155:bdad1d0e:6e3cbad6
Events : 112031
Number Major Minor RaidDevice State
4 8 64 0 active sync /dev/sde
1 8 16 1 active sync /dev/sdb
3 8 32 2 active sync /dev/sdc
0 8 0 - spare /dev/sda
Then the following happened:
The disk /dev/sdd broke and was thrown out of the array (this happened
like one month ago already).
Somehow the spare was not activated and so the array degraded was inactive.
I activated the spare and the array was syncing.
After that finished I manually failed and removed /dev/sdd from the
array and physically disconnected it as well.
I thought i could reassemble the array with the remaining three disks
but this currently fails as follows:
(Please note that the new /dev/sdd was previously /dev/sde)
mdadm --examine /dev/sd[b-z]
/dev/sdb:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : 7b0eee59:07f87155:bdad1d0e:6e3cbad6
Name : NAS:0 (local to host NAS)
Creation Time : Wed Jan 7 18:14:37 2015
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 5860274096 (2794.40 GiB 3000.46 GB)
Array Size : 8790405120 (8383.18 GiB 9001.37 GB)
Used Dev Size : 5860270080 (2794.39 GiB 3000.46 GB)
Data Offset : 259072 sectors
Super Offset : 8 sectors
Unused Space : before=258984 sectors, after=4016 sectors
State : clean
Device UUID : a286ad29:114690eb:9bb2d0a3:3615f52c
Internal Bitmap : 8 sectors from superblock
Update Time : Tue Jan 7 09:08:03 2020
Bad Block Log : 512 entries available at offset 72 sectors
Checksum : e3007322 - correct
Events : 273134
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 1
Array State : AAA. ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdc:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : 7b0eee59:07f87155:bdad1d0e:6e3cbad6
Name : NAS:0 (local to host NAS)
Creation Time : Wed Jan 7 18:14:37 2015
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 5860274096 (2794.40 GiB 3000.46 GB)
Array Size : 8790405120 (8383.18 GiB 9001.37 GB)
Used Dev Size : 5860270080 (2794.39 GiB 3000.46 GB)
Data Offset : 259072 sectors
Super Offset : 8 sectors
Unused Space : before=258984 sectors, after=4016 sectors
State : clean
Device UUID : c60b01fc:2eaad12c:c3a619af:be9b687d
Internal Bitmap : 8 sectors from superblock
Update Time : Tue Jan 7 09:08:03 2020
Bad Block Log : 512 entries available at offset 72 sectors
Checksum : 5251d716 - correct
Events : 273134
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 2
Array State : AAA. ('A' == active, '.' == missing, 'R' == replacing)
mdadm: No md superblock detected on /dev/sdd.
When i try to assemble the array with the two (hopefully) fine drives it fails:
mdadm --assemble /dev/md0 /dev/sd[bc] --verbose
mdadm: looking for devices for /dev/md0
mdadm: /dev/sdb is identified as a member of /dev/md0, slot 1.
mdadm: /dev/sdc is identified as a member of /dev/md0, slot 2.
mdadm: no uptodate device for slot 0 of /dev/md0
mdadm: added /dev/sdc to /dev/md0 as 2
mdadm: no uptodate device for slot 3 of /dev/md0
mdadm: added /dev/sdb to /dev/md0 as 1
mdadm: /dev/md0 assembled from 2 drives - not enough to start the array.
Then the array is inactive out of the two disks but is considered as
raid0 instead of raid5:
mdadm --detail -v /dev/md0
/dev/md0:
Version : 1.2
Raid Level : raid0
Total Devices : 2
Persistence : Superblock is persistent
State : inactive
Working Devices : 2
Name : NAS:0 (local to host NAS)
UUID : 7b0eee59:07f87155:bdad1d0e:6e3cbad6
Events : 273134
Number Major Minor RaidDevice
- 8 32 - /dev/sdc
- 8 16 - /dev/sdb
cat /proc/mdstat
Personalities :
md0 : inactive sdc[3](S) sdb[1](S)
5860274096 blocks super 1.2
unused devices: <none>
When i try to add the remaining disk it fails as follows:
mdadm --add /dev/md0 /dev/sdd
mdadm: Cannot get array info for /dev/md0
I am not sure how i should continue to get the array working again and
i hope that you can help me here :)
Thanks in advance,
Marco
