NAS542 resync loop

linuxopa

NAS542, 4 drives, Raid5, no spare, Firmware V5.21(ABAG.14)
For some time now, my NAS542 has been resynchronizing almost constantly. smartctl shows no errors on the 4 drives, mdadm --examine /dev/sd[abcd]3 also shows nothing unusual. Where can I find the trigger?

Mijzelf

So what did 'mdadm --examine /dev/sd[abcd]3' say? And is it always the same disk which is resyncing?

linuxopa

>So what did 'mdadm --examine /dev/sd[abcd]3' say?

~ # mdadm --examine /dev/sd[abcd]3
/dev/sda3:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 33f5a2f7:c031c1a9:bb1e6599:b560f407
Name : NAS542:2 (local to host NAS542)
Creation Time : Thu May 6 14:47:18 2021
Raid Level : raid5
Raid Devices : 4

Avail Dev Size : 3898767360 (1859.08 GiB 1996.17 GB)
Array Size : 5848151040 (5577.23 GiB 5988.51 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : active
Device UUID : c5bb5b9e:4b700eb4:87f8ed8f:5b0c2c65

Update Time : Sat Jun 22 16:34:55 2024
   Checksum : 3293770e - correct
     Events : 9712

     Layout : left-symmetric
 Chunk Size : 64K

Device Role : Active device 0
Array State : AAAA ('A' == active, '.' == missing)
/dev/sdb3:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 33f5a2f7:c031c1a9:bb1e6599:b560f407
Name : NAS542:2 (local to host NAS542)
Creation Time : Thu May 6 14:47:18 2021
Raid Level : raid5
Raid Devices : 4

Avail Dev Size : 3898767360 (1859.08 GiB 1996.17 GB)
Array Size : 5848151040 (5577.23 GiB 5988.51 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : active
Device UUID : b855ccea:2ba8de64:083c3d9c:06b381c7

Update Time : Sat Jun 22 16:34:55 2024
   Checksum : 9e79330c - correct
     Events : 9712

     Layout : left-symmetric
 Chunk Size : 64K

Device Role : Active device 1
Array State : AAAA ('A' == active, '.' == missing)
/dev/sdc3:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 33f5a2f7:c031c1a9:bb1e6599:b560f407
Name : NAS542:2 (local to host NAS542)
Creation Time : Thu May 6 14:47:18 2021
Raid Level : raid5
Raid Devices : 4

Avail Dev Size : 3898767360 (1859.08 GiB 1996.17 GB)
Array Size : 5848151040 (5577.23 GiB 5988.51 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : active
Device UUID : efe096ae:ddcd3574:1bc65cf5:882d53f9

Update Time : Sat Jun 22 16:34:55 2024
   Checksum : fc8be88c - correct
     Events : 9712

     Layout : left-symmetric
 Chunk Size : 64K

Device Role : Active device 2
Array State : AAAA ('A' == active, '.' == missing)
/dev/sdd3:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 33f5a2f7:c031c1a9:bb1e6599:b560f407
Name : NAS542:2 (local to host NAS542)
Creation Time : Thu May 6 14:47:18 2021
Raid Level : raid5
Raid Devices : 4

Avail Dev Size : 3898767360 (1859.08 GiB 1996.17 GB)
Array Size : 5848151040 (5577.23 GiB 5988.51 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : active
Device UUID : e7d4bbc6:1c2f01fb:32078fd9:9c644fea

Update Time : Sat Jun 22 16:34:55 2024
   Checksum : 70aab5f0 - correct
     Events : 9712

     Layout : left-symmetric
 Chunk Size : 64K

Device Role : Active device 3
Array State : AAAA ('A' == active, '.' == missing)

>And is it always the same disk which is resyncing?

Volume1

smartctl_drives_0-3.txt

smartctl -x all drives

linuxopa

drive sdb: "SCT Error Recovery Control command not supported"

I will replace the disk
may it help…

Mijzelf

Did you get that 'mdadm —examine' while it was resyncing? In that case it should have been visible. How much time does a resync take? Could it be that it's the firmware partition array (2GB) which is resyncing?

You can get more info from

cat /proc/mdstat

which gives the array, the rebuild status and the exact member which is resycing.

linuxopa

>How much time does a resync take?

around 20h

I have stopped all jobs that write to the nas.
we'll see tomorrow, in the meantime 2 disks are already complaining.
I will swap them when resync is hopefully done.

~ # cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md2 : active raid5 sda3[5] sdb3[4] sdd3[7] sdc3[6]
5848151040 blocks super 1.2 level 5, 64k chunk, algorithm 2 [4/3] [U_UU]
[>....................] recovery = 0.1% (2254316/1949383680) finish=3311.6min speed=9799K/sec

md1 : active raid1 sda2[5] sdd2[7] sdc2[6] sdb2[4]
1998784 blocks super 1.2 [4/4] [UUUU]

md0 : active raid1 sda1[5] sdd1[7] sdc1[6] sdb1[4]
1997760 blocks super 1.2 [4/4] [UUUU]

unused devices: <none>

linuxopa

fck. 2 drives died. after replacement it's ok.