Hello,
I had the Synology DS1515+ (5 drive slots) and used to have one single Storage Pool consists of 4 drives (two 4TB drives and two 8TB drives, using SHR configuration), the extra slot on the machine was not in use. One day Drive #4 crashed and the Storage Pool went in Degraded state. I bought a new 16TB disk hoping to replace it and recover the Storage Pool.
But stupid me, I mistakenly took out the healthy Drive #3, replaced it with the new disk, and booted up the machine. I then clicked the Online Assemble option from the overview page in the Storage Manager app, but it had always failed to do so. After a few attempts and reboots, somehow I got to see a Repair option, I clicked it and it starts repairing the Storage Pool, with two originally healthy Drives #1 & #2, the mistakenly replaced 16TB Drive #3, and the originally crashed Drive #4. Up to this point, I had access to the data via the File Manager app, but the response was very slow.
After that, I moved the 16TB disk out from Drive #3 to Drive #5, and re-inserted the original 4TB healthy disk back into Drive #3. Now Drive #3 becomes Not Initialized (Healthy), and Drive #5 becomes Crashed (Healthy). I no longer have access to the storage via File Manager. But fortunately, the files seems to be accessible via the SSH terminal.
Any advice or guidance on my journey to recover the Storage Pool and the data would be gratefully received.
$ cat /proc/mdstat
Personalities : [raid1] [raid6] [raid5] [raid4] [raidF1]
md3 : active raid1 sdd6[0]
3906998912 blocks super 1.2 [2/1] [U_]
md2 : active raid5 sda5[4] sde5[5] sdb5[7]
11706562368 blocks super 1.2 level 5, 64k chunk, algorithm 2 [4/3] [UU_U]
md1 : active raid1 sda2[0] sdd2[2] sdb2[1]
2097088 blocks [5/3] [UUU__]
md0 : active raid1 sdb1[0] sda1[3] sdd1[1]
2490176 blocks [5/3] [UU_U_]
unused devices: <none>
$ vgdisplay --verbose
Using volume group(s) on command line.
--- Volume group ---
VG Name vg1000
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 2
Act PV 2
VG Size 14.54 TiB
PE Size 4.00 MiB
Total PE 3811904
Alloc PE / Size 3811904 / 14.54 TiB
Free PE / Size 0 / 0
VG UUID 1e1yFU-tU4H-iDgZ-biKn-nD1S-nK4V-P2lohD
--- Logical volume ---
LV Path /dev/vg1000/lv
LV Name lv
VG Name vg1000
LV UUID AXdWh7-vAGX-2d7U-wXtb-quk3-LsHy-kPmdBx
LV Write Access read/write
LV Creation host, time ,
LV Status available
# open 1
LV Size 14.54 TiB
Current LE 3811904
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 768
Block device 253:0
--- Physical volumes ---
PV Name /dev/md2
PV UUID hK1a7S-pdX1-5hjp-m53A-Tlpy-Jk9L-McEdHH
PV Status allocatable
Total PE / Free PE 2858047 / 0
PV Name /dev/md3
PV UUID cJCeIW-KpCY-ez6a-JFk1-iRmT-djVM-Trec1B
PV Status allocatable
Total PE / Free PE 953857 / 0
$ lvdisplay --verbose
Using logical volume(s) on command line.
--- Logical volume ---
LV Path /dev/vg1000/lv
LV Name lv
VG Name vg1000
LV UUID AXdWh7-vAGX-2d7U-wXtb-quk3-LsHy-kPmdBx
LV Write Access read/write
LV Creation host, time ,
LV Status available
# open 1
LV Size 14.54 TiB
Current LE 3811904
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 768
Block device 253:0
$ pvdisplay --verbose
Using physical volume(s) on command line.
Wiping cache of LVM-capable devices
--- Physical volume ---
PV Name /dev/md2
VG Name vg1000
PV Size 10.90 TiB / not usable 1.81 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 2858047
Free PE 0
Allocated PE 2858047
PV UUID hK1a7S-pdX1-5hjp-m53A-Tlpy-Jk9L-McEdHH
--- Physical volume ---
PV Name /dev/md3
VG Name vg1000
PV Size 3.64 TiB / not usable 640.00 KiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 953857
Free PE 0
Allocated PE 953857
PV UUID cJCeIW-KpCY-ez6a-JFk1-iRmT-djVM-Trec1B
$ df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/md0 2385528 1920488 346256 85% /
devtmpfs 8208924 0 8208924 0% /dev
tmpfs 8212972 4 8212968 1% /dev/shm
tmpfs 8212972 15568 8197404 1% /run
tmpfs 8212972 0 8212972 0% /sys/fs/cgroup
tmpfs 8212972 1092 8211880 1% /tmp
/dev/mapper/cachedev_0 14989016436 14486635592 502380844 97% /volume1
$ mdadm --detail /dev/md0
/dev/md0:
Version : 0.90
Creation Time : Mon Nov 30 17:33:21 2015
Raid Level : raid1
Array Size : 2490176 (2.37 GiB 2.55 GB)
Used Dev Size : 2490176 (2.37 GiB 2.55 GB)
Raid Devices : 5
Total Devices : 3
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Sat Sep 2 14:02:50 2023
State : active, degraded
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
UUID : 7622664e:1657328c:3017a5a8:c86610be
Events : 0.37057847
Number Major Minor RaidDevice State
0 8 17 0 active sync /dev/sdb1
1 8 49 1 active sync /dev/sdd1
- 0 0 2 removed
3 8 1 3 active sync /dev/sda1
- 0 0 4 removed
$ mdadm --detail /dev/md1
/dev/md1:
Version : 0.90
Creation Time : Sun Apr 28 18:35:40 2019
Raid Level : raid1
Array Size : 2097088 (2047.94 MiB 2147.42 MB)
Used Dev Size : 2097088 (2047.94 MiB 2147.42 MB)
Raid Devices : 5
Total Devices : 3
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Wed Jan 1 08:12:37 2014
State : clean, degraded
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
UUID : abcf619a:3398cc73:e7b2e964:f815f961 (local to host NAS)
Events : 0.45611
Number Major Minor RaidDevice State
0 8 2 0 active sync /dev/sda2
1 8 18 1 active sync /dev/sdb2
2 8 50 2 active sync /dev/sdd2
- 0 0 3 removed
- 0 0 4 removed
$ mdadm --detail /dev/md2
/dev/md2:
Version : 1.2
Creation Time : Mon Nov 30 18:19:21 2015
Raid Level : raid5
Array Size : 11706562368 (11164.25 GiB 11987.52 GB)
Used Dev Size : 3902187456 (3721.42 GiB 3995.84 GB)
Raid Devices : 4
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Sat Sep 2 13:32:07 2023
State : clean, degraded
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 64K
Name : NAS:2 (local to host NAS)
UUID : 5ffcb2a1:80bc4d39:7f19eb5f:2d922605
Events : 753119
Number Major Minor RaidDevice State
4 8 5 0 active sync /dev/sda5
7 8 21 1 active sync /dev/sdb5
- 0 0 2 removed
5 8 69 3 active sync /dev/sde5
$ mdadm --detail /dev/md3
/dev/md3:
Version : 1.2
Creation Time : Mon Dec 3 12:19:09 2018
Raid Level : raid1
Array Size : 3906998912 (3726.00 GiB 4000.77 GB)
Used Dev Size : 3906998912 (3726.00 GiB 4000.77 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Sat Sep 2 14:03:35 2023
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : NAS:3 (local to host NAS)
UUID : adf75971:3ab713a6:ae03a0ce:ac3dc03d
Events : 52290
Number Major Minor RaidDevice State
0 8 54 0 active sync /dev/sdd6
- 0 0 1 removed