Hi !
I just did a test for you (and for being sure myself for future, and
before saying anything wrong).
Created 4 files of 1536 MB (into a 8GB RAM Disk so it's faster than
ever) + 1 for the coming replacement:
dd if=/dev/zero of=R1.img bs=1024k status=progress count=1536
dd if=/dev/zero of=R2.img bs=1024k status=progress count=1536
dd if=/dev/zero of=R3.img bs=1024k status=progress count=1536
dd if=/dev/zero of=R4.img bs=1024k status=progress count=1536
dd if=/dev/zero of=R5.img bs=1024k status=progress count=1536
Made them available as block devices:
losetup /dev/loop0 /home/user/RAMFS/R1.img
losetup /dev/loop1 /home/user/RAMFS/R2.img
losetup /dev/loop2 /home/user/RAMFS/R3.img
losetup /dev/loop3 /home/user/RAMFS/R4.img
losetup /dev/loop4 /home/user/RAMFS/R5.img
Created my RAID 10 with 4 disks:
mdadm --create /dev/md0 --level=10 --raid-devices=4 /dev/loop0
/dev/loop1 /dev/loop2 /dev/loop3
Which gives:
oot@Octocrobe:/home/user/RAMFS# mdadm --detail /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Tue May 14 17:59:28 2019
Raid Level : raid10
Array Size : 3143680 (3.00 GiB 3.22 GB)
Used Dev Size : 1571840 (1535.00 MiB 1609.56 MB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Tue May 14 18:05:55 2019
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0
Layout : near=2
Chunk Size : 512K
Name : Octocrobe:0 (local to host Octocrobe)
UUID : f9876be6:2a574cf3:3824348e:2438479e
Events : 17
Number Major Minor RaidDevice State
0 7 0 0 active sync set-A /dev/loop0
1 7 1 1 active sync set-B /dev/loop1
2 7 2 2 active sync set-A /dev/loop2
3 7 3 3 active sync set-B /dev/loop3
I wrote something to the RAID (do not do this over valuable filesystem
or data!) in order to have a way to control data integrity later.
shred -n 1 -v /dev/md0
Checked the sha1 resulting values of data available on the array, then
members data area (with 2048 sectors data offset, so 1 MB to skip)
887db7d3f046242e9f99dd330cc628d2b3f7a5f9 /dev/md0
dd if=/home/user/RAMFS/R1.img bs=1024k skip=1 | sha1sum:
954497d3e591bdb3998e5ccf35a639d2c2894bb8
dd if=/home/user/RAMFS/R2.img bs=1024k skip=1 | sha1sum:
954497d3e591bdb3998e5ccf35a639d2c2894bb8
dd if=/home/user/RAMFS/R3.img bs=1024k skip=1 | sha1sum:
1fad602e67a218391406dafa04c7ecba000ecaf7
dd if=/home/user/RAMFS/R4.img bs=1024k skip=1 | sha1sum:
1fad602e67a218391406dafa04c7ecba000ecaf7
For the still not used one: 23543e573e0e1fbfcec24dc7441395c50dd61bd6
Failed the 3rd member:
mdadm --manage /dev/md0 --fail /dev/loop2
Details :
Number Major Minor RaidDevice State
0 7 0 0 active sync set-A /dev/loop0
1 7 1 1 active sync set-B /dev/loop1
- 0 0 2 removed
3 7 3 3 active sync set-B /dev/loop3
2 7 2 - faulty /dev/loop2
Not mandatory: trying to stop and assemble back the array, just to see:
mdadm --stop /dev/md0
mdadm --assemble /dev/md0 /dev/loop0 /dev/loop1 /dev/loop2 /dev/loop3
mdadm: /dev/md0 has been started with 3 drives (out of 4).
Details: /dev/loop2 disappeared from mdadm --detail, but it's still
working the exact same way.
Number Major Minor RaidDevice State
0 7 0 0 active sync set-A /dev/loop0
1 7 1 1 active sync set-B /dev/loop1
- 0 0 2 removed
3 7 3 3 active sync set-B /dev/loop3
Added the new one:
mdadm --manage /dev/md0 --add /dev/loop4
Details:
Rebuild Status : 78% complete
Name : Octocrobe:0 (local to host Octocrobe)
UUID : b81ed231:11636921:fb6e5c51:7003143d
Events : 36
Number Major Minor RaidDevice State
0 7 0 0 active sync set-A /dev/loop0
1 7 1 1 active sync set-B /dev/loop1
4 7 4 2 spare rebuilding /dev/loop4
3 7 3 3 active sync set-B /dev/loop3
Then it seems to be fine:
dd if=/home/user/RAMFS/R5.img bs=1024k skip=1 | sha1sum :
1fad602e67a218391406dafa04c7ecba000ecaf7
root@Octocrobe:/home/user/RAMFS# mdadm --detail /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Tue May 14 17:59:28 2019
Raid Level : raid10
Array Size : 3143680 (3.00 GiB 3.22 GB)
Used Dev Size : 1571840 (1535.00 MiB 1609.56 MB)
Raid Devices : 4
Total Devices : 5
Persistence : Superblock is persistent
Update Time : Tue May 14 18:29:01 2019
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 1
Spare Devices : 0
Layout : near=2
Chunk Size : 512K
Name : Octocrobe:0 (local to host Octocrobe)
UUID : f9876be6:2a574cf3:3824348e:2438479e
Events : 37
Number Major Minor RaidDevice State
0 7 0 0 active sync set-A /dev/loop0
1 7 1 1 active sync set-B /dev/loop1
4 7 4 2 active sync set-A /dev/loop4
3 7 3 3 active sync set-B /dev/loop3
Another way is:
mdadm /dev/md0 --re-add /dev/yourFailedDrive
mdadm --manage /dev/md0 --add /dev/yourNewDrive --replace
/dev/yourFailedDrive --with /dev/yourNewDrive
At the end, the new drive content is conform too. This way is supposed
to attempt reading over the replaced drive instead of reading over the
others ones, but I guess your failed drive won't be available anymore ;)
so it may be not useful.
Good luck!
Julien
On 5/14/19 5:48 PM, Eric Valette wrote:
I have a dedicated hardware nas that runs a self maintained debian 10.
before the hardware disk problem (before/after)
sda : system disk OK/OK no raid
sdb : first disk of the raid10 array OK/OK
sdc : second disk of the raid10 array OK/OK
sdd : third disk of the raid10 array OK/KO
sde : fourth disk of the raid10 array OK/OK but is now sdd
sdf : spare disk for the array is now sde
After the failure the BIOS does not detect the original third disk. Disk
are renamed and I think sde has become sdd and sdf -> sde
Below are more detailed info. Feel free to ask for other things as I can
log into the machine via ssh
So I have several questions :
1) How to I repair the raid10 array using the spare disk without
replacing the faulty one immediately?
2) What should I do once I receive the new disk (hopefully soon)
3) Is there a way to use persistent naming for disk array?
Sorry to annoy you but my kid wants to see a film on the nas and annoys
me badly. And I prefer to ask rather than doing mistakes.
Thanks for any
mdadm --examine /dev/sdb
/dev/sdb:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
root@nas2:~# mdadm --examine /dev/sdb
/dev/sdb:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
root@nas2:~# mdadm --examine /dev/sdb1
/dev/sdb1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 6abe1f20:90c629de:fadd8dc0:ca14c928
Name : nas2:0 (local to host nas2)
Creation Time : Wed Jun 20 23:56:59 2012
Raid Level : raid10
Raid Devices : 4
Avail Dev Size : 5860268943 (2794.39 GiB 3000.46 GB)
Array Size : 5860268032 (5588.79 GiB 6000.91 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
Unused Space : before=262064 sectors, after=911 sectors
State : clean
Device UUID : ce9d878a:37a4f3a3:936bd905:c4ed9970
Update Time : Wed May 8 11:39:40 2019
Checksum : cf841c9f - correct
Events : 1193
Layout : near=2
Chunk Size : 512K
Device Role : Active device 0
Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
root@nas2:~# mdadm --examine /dev/sdc
/dev/sdc:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
root@nas2:~# mdadm --examine /dev/sdc1
/dev/sdc1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 6abe1f20:90c629de:fadd8dc0:ca14c928
Name : nas2:0 (local to host nas2)
Creation Time : Wed Jun 20 23:56:59 2012
Raid Level : raid10
Raid Devices : 4
Avail Dev Size : 5860268943 (2794.39 GiB 3000.46 GB)
Array Size : 5860268032 (5588.79 GiB 6000.91 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
Unused Space : before=262064 sectors, after=911 sectors
State : clean
Device UUID : 8c89bdf8:4f3f8ace:c15b5634:7a874071
Update Time : Wed May 8 11:39:40 2019
Checksum : 97744edb - correct
Events : 1193
Layout : near=2
Chunk Size : 512K
Device Role : Active device 1
Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
root@nas2:~# mdadm --examine /dev/sdd
/dev/sdd:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
root@nas2:~# mdadm --examine /dev/sdd1
/dev/sdd1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 6abe1f20:90c629de:fadd8dc0:ca14c928
Name : nas2:0 (local to host nas2)
Creation Time : Wed Jun 20 23:56:59 2012
Raid Level : raid10
Raid Devices : 4
Avail Dev Size : 5860268943 (2794.39 GiB 3000.46 GB)
Array Size : 5860268032 (5588.79 GiB 6000.91 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
Unused Space : before=262064 sectors, after=911 sectors
State : clean
Device UUID : c97b767a:84d2e7e2:52557d30:51c39784
Update Time : Wed May 8 11:39:40 2019
Checksum : 3d08e837 - correct
Events : 1193
Layout : near=2
Chunk Size : 512K
Device Role : Active device 3
Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
root@nas2:~# mdadm --examine /dev/sde
/dev/sde:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
root@nas2:~# mdadm --examine /dev/sde1
/dev/sde1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 6abe1f20:90c629de:fadd8dc0:ca14c928
Name : nas2:0 (local to host nas2)
Creation Time : Wed Jun 20 23:56:59 2012
Raid Level : raid10
Raid Devices : 4
Avail Dev Size : 5860268943 (2794.39 GiB 3000.46 GB)
Array Size : 5860268032 (5588.79 GiB 6000.91 GB)
Used Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
Unused Space : before=262064 sectors, after=911 sectors
State : clean
Device UUID : 82667e81:a6158319:85e0282e:845eec1c
Update Time : Wed May 8 11:00:29 2019
Checksum : 10ac3349 - correct
Events : 1193
Layout : near=2
Chunk Size : 512K
Device Role : spare
Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
root@nas2:~#
mdadm --detail /dev/md0
/dev/md0:
Version : 1.2
Raid Level : raid0
Total Devices : 4
Persistence : Superblock is persistent
State : inactive
Working Devices : 4
Name : nas2:0 (local to host nas2)
UUID : 6abe1f20:90c629de:fadd8dc0:ca14c928
Events : 1193
Number Major Minor RaidDevice
- 8 65 - /dev/sde1
- 8 49 - /dev/sdd1
- 8 33 - /dev/sdc1
- 8 17 - /dev/sdb1
cat /proc/mdstat
Personalities : [raid10]
md0 : inactive sdc1[1](S) sdb1[0](S) sde1[4](S) sdd1[3](S)
11720537886 blocks super 1.2
unused devices: <none>
