hello,
a broken synology raid5 ended up on my desk. the raid was broken for
quite some time, but i got it from the client just a few days back.
the raid consisted of 5 disks (no spares, all used):
disk 1 (sdca): according to my understanding, it was removed from the
raid, then re-added, but the synchronization was interrupted, so it
cannot be used to restore the raid
disk 2 (sdcb): is ok and up to date
disk 3 (sdcc): seems to be up to date, still spinning, but there are
many issues with bad sectors
disk 4 (sdcd): is ok and up to date
disk 5 (sdce): is ok and up to date
the raid ran in degraded mode for over two months, client trying to make
a copy of the data from it.
i made copies of the disk images from disks 1, 2, 4, and 5, at the state
shown below. i didn't attempt to make a copy of disk 3 so far. since
then i re-assembled the raid from disk 2-5 so the number of events on
the disk 3 is now a bit higher then on the copies of the disk images.
according to my understanding, as the disk 1 never finished the sync, i
cannot use it to recover the data, so the only way to recover the data
is to assemble the raid in degraded mode using disk 2-5, if i ever
succeed to make a copy of the disk 3. i'd just like to verify that my
understanding is correct and there is no other way to attempt to recover
the data. of course any hints are welcome.
here is the info from the partitions of the raid:
/dev/sdca5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x2
Array UUID : f697911c:bc85b162:13eaba4e:d1152a4f
Name : DS_KLIENT:4
Creation Time : Tue Mar 31 11:40:19 2020
Raid Level : raid5
Raid Devices : 5
Avail Dev Size : 15618390912 (7447.43 GiB 7996.62 GB)
Array Size : 31236781824 (29789.72 GiB 31986.46 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Recovery Offset : 4910216 sectors
Unused Space : before=1968 sectors, after=0 sectors
State : clean
Device UUID : 681c6c33:49df0163:bb4271d4:26c0c76d
Update Time : Tue Jun 4 18:35:54 2024
Checksum : cf45a6c1 - correct
Events : 60223
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 0
Array State : AAAAA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdcb5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : f697911c:bc85b162:13eaba4e:d1152a4f
Name : DS_KLIENT:4
Creation Time : Tue Mar 31 11:40:19 2020
Raid Level : raid5
Raid Devices : 5
Avail Dev Size : 15618390912 (7447.43 GiB 7996.62 GB)
Array Size : 31236781824 (29789.72 GiB 31986.46 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=0 sectors
State : clean
Device UUID : 0f23d7cd:b93301a9:5289553e:286ab6f0
Update Time : Wed Aug 14 15:09:24 2024
Checksum : 9c93703e - correct
Events : 60286
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 1
Array State : .AAAA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdcc5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : f697911c:bc85b162:13eaba4e:d1152a4f
Name : DS_KLIENT:4
Creation Time : Tue Mar 31 11:40:19 2020
Raid Level : raid5
Raid Devices : 5
Avail Dev Size : 15618390912 (7447.43 GiB 7996.62 GB)
Array Size : 31236781824 (29789.72 GiB 31986.46 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=0 sectors
State : clean
Device UUID : 1d1c04b4:24dabd8d:235afb7d:1494b8eb
Update Time : Wed Aug 14 12:42:26 2024
Checksum : a224ec08 - correct
Events : 60283
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 2
Array State : .AAAA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdcd5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : f697911c:bc85b162:13eaba4e:d1152a4f
Name : DS_KLIENT:4
Creation Time : Tue Mar 31 11:40:19 2020
Raid Level : raid5
Raid Devices : 5
Avail Dev Size : 15618390912 (7447.43 GiB 7996.62 GB)
Array Size : 31236781824 (29789.72 GiB 31986.46 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=0 sectors
State : clean
Device UUID : 76698d3f:e9c5a397:05ef7553:9fd0af16
Update Time : Wed Aug 14 15:09:24 2024
Checksum : 38061500 - correct
Events : 60286
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 4
Array State : .AAAA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdce5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : f697911c:bc85b162:13eaba4e:d1152a4f
Name : DS_KLIENT:4
Creation Time : Tue Mar 31 11:40:19 2020
Raid Level : raid5
Raid Devices : 5
Avail Dev Size : 15618390912 (7447.43 GiB 7996.62 GB)
Array Size : 31236781824 (29789.72 GiB 31986.46 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
Unused Space : before=1968 sectors, after=0 sectors
State : clean
Device UUID : 9c7077f8:3120195a:1af11955:6bcebd99
Update Time : Wed Aug 14 15:09:24 2024
Checksum : 38177651 - correct
Events : 60286
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 3
Array State : .AAAA ('A' == active, '.' == missing, 'R' == replacing)
thank you for your help.
miroslav
