Fredrik Erlandsson
PhD in Computer science, data scientist at Consid AB.
Migrate from one 512 GB SSD disk to a 1TB SSD disk on Synology DSM with no free disk slots
2021-04-28My “old” (Fri Oct 26 15:45:49 2018) 512 GB SSD disk have been alarming that it is running end of life so a new 1TB SSD disk will replace it. This is my own notes on what I did.
The initial stage is a 512 GB SSD in slot 1 and a 12 TB disk in slot 2. Both are configured as SHR.
Stage 1, remove 12 TB disk
The Synology were shut down and the 12 TB disk was replaced with the 1 TB disk. This went as planned and both disks showed up and I added the new disk to the Storage pool which started to rebuild. After ~12 hours the rebuild was completed so I replaced the faulty 512 GB disk with the 12 TB disk (hotplug), and were hopefull that DSM would automatically detect everything on the 12 TB disk. Unfortunatly DSM didn’t detect the Storage Pool on the big disk.
Stage 2, boot with just the 12TB disk
The Synology were shut down and the 1TB disk was removed. When the Synology was powered on again everything on the 12TB disk was showing. After some problem with accessing the Synology over SSH (I had ofcourse dissabled the PasswordAuthentication on sshd, and remounted the homes folder to space on the SSD. Which was fixed with sed -i '/^PasswordAuthentication/{s/.*/#&/;:A;n;bA}' /etc/ssh/sshd_config as a Task from DSM).
My thought here was that DSM didn’t detect the LVMs on the 12 TB correctly when booted from the SSD system. DSM is using a md device for the system partitions. In stage 1 the system on the SSD couldn’t detect the configuration correctly. However, the output from vgdisplay -v just returned No volume groups found.. So the next step was to look at what’s mounted and try to make sense from that.
root@Synology:/# mount
/dev/md0 on / type ext4 (rw,relatime,journal_checksum,barrier,data=ordered)
none on /dev type devtmpfs (rw,nosuid,noexec,relatime,size=4042584k,nr_inodes=1010646,mode=755)
none on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
none on /proc type proc (rw,nosuid,nodev,noexec,relatime)
none on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
/tmp on /tmp type tmpfs (rw,relatime)
/run on /run type tmpfs (rw,nosuid,nodev,relatime,mode=755)
/dev/shm on /dev/shm type tmpfs (rw,nosuid,nodev,relatime)
none on /sys/fs/cgroup type tmpfs (rw,relatime,size=4k,mode=755)
cgmfs on /run/cgmanager/fs type tmpfs (rw,relatime,size=100k,mode=755)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,relatime,cpuset,release_agent=/run/cgmanager/agents/cgm-release-agent.cpuset,clone_children)
cgroup on /sys/fs/cgroup/cpu type cgroup (rw,relatime,cpu,release_agent=/run/cgmanager/agents/cgm-release-agent.cpu)
cgroup on /sys/fs/cgroup/cpuacct type cgroup (rw,relatime,cpuacct,release_agent=/run/cgmanager/agents/cgm-release-agent.cpuacct)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,relatime,memory,release_agent=/run/cgmanager/agents/cgm-release-agent.memory)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,relatime,devices,release_agent=/run/cgmanager/agents/cgm-release-agent.devices)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,relatime,freezer,release_agent=/run/cgmanager/agents/cgm-release-agent.freezer)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,relatime,blkio,release_agent=/run/cgmanager/agents/cgm-release-agent.blkio)
none on /proc/bus/usb type devtmpfs (rw,nosuid,noexec,relatime,size=4042584k,nr_inodes=1010646,mode=755)
none on /sys/kernel/debug type debugfs (rw,relatime)
securityfs on /sys/kernel/security type securityfs (rw,relatime)
/dev/md2 on /volume2 type btrfs (rw,relatime,synoacl,space_cache=v2,auto_reclaim_space,metadata_ratio=50)
none on /config type configfs (rw,relatime)
root@Synology:/# cat /proc/partitions
major minor #blocks name
8 16 11718885376 sdb
8 17 2490240 sdb1
8 18 2097152 sdb2
8 19 11714064384 sdb3
9 0 2490176 md0
9 1 2097088 md1
9 2 11714063360 md2
135 240 122880 synoboot
135 241 16033 synoboot1
135 242 96390 synoboot2
The interesting parts here are the /dev/md lines. So an investigation on mdadm resulted in this:
root@Synology:/# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md2 : active raid1 sdb3[0]
11714063360 blocks super 1.2 [1/1] [U]
md1 : active raid1 sdb2[1]
2097088 blocks [2/1] [_U]
md0 : active raid1 sdb1[0]
2490176 blocks [2/1] [U_]
unused devices: <none>
root@synology:/# mdadm --detail /dev/md*
/dev/md0:
Version : 0.90
Creation Time : Sat Jan 7 19:55:24 2017
Raid Level : raid1
Array Size : 2490176 (2.37 GiB 2.55 GB)
Used Dev Size : 2490176 (2.37 GiB 2.55 GB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Wed Apr 28 13:26:30 2021
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
UUID : faaf8e9e:d3c4d9b3:3017a5a8:c86610be
Events : 0.1575021
Number Major Minor RaidDevice State
0 8 17 0 active sync /dev/sdb1
- 0 0 1 removed
/dev/md1:
Version : 0.90
Creation Time : Wed Jul 10 12:21:48 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 : 2
Total Devices : 1
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Wed Apr 28 12:44:01 2021
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
UUID : 56d6c602:91c22c01:c03470a7:6e080e63 (local to host SynHome)
Events : 0.55
Number Major Minor RaidDevice State
- 0 0 0 removed
1 8 18 1 active sync /dev/sdb2
/dev/md2:
Version : 1.2
Creation Time : Sun Jan 13 12:30:57 2019
Raid Level : raid1
Array Size : 11714063360 (11171.40 GiB 11995.20 GB)
Used Dev Size : 11714063360 (11171.40 GiB 11995.20 GB)
Raid Devices : 1
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Wed Apr 28 12:56:38 2021
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : SynHome:2 (local to host SynHome)
UUID : 6ffcf44d:8e2b976b:97d1189f:883f3f08
Events : 78
Number Major Minor RaidDevice State
0 8 19 0 active sync /dev/sdb3
What’s interesting here is the fact that /dev/sdb3 is configured as a raid1 device and is directly mounted on /volume2. My fear was that I needed to recreate the md2 once the SSD was inserted again. So I shout down the Synology again and inserted the 1TB SSD.
Stage 3, after reboot (12 TB disk in slot 2, 1 TB disk in slot 1)
Magically both disks show up. This time DSM used the system volume from the 12TB disk, so the system volume had to be restored on the SSD disk (from DSM).
The Storage Pool for the 1TB did however show up as degraded (as it was missing one disk). Back in with SSH and this is the result from mdadm:
root@Synology:/# mdadm --detail /dev/md2
/dev/md2:
Version : 1.2
Creation Time : Fri Oct 26 15:45:49 2018
Raid Level : raid1
Array Size : 495274816 (472.33 GiB 507.16 GB)
Used Dev Size : 495274816 (472.33 GiB 507.16 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Wed Apr 28 15:15:00 2021
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : SynHome:2 (local to host SynHome)
UUID : bf5d1657:09009110:465ee7eb:16143369
Events : 105357
Number Major Minor RaidDevice State
- 0 0 0 removed
1 8 5 1 active sync /dev/sda5
As shown one disk is missing (removed) and the State shows clean, degraded. mdadm can however be fixed for this with the --grow -n 1 parameter.
root@Synology:/# mdadm --grow -n 1 --force /dev/md2
raid_disks for /dev/md2 set to 1
root@Synology:/# mdadm --detail /dev/md2
/dev/md2:
Version : 1.2
Creation Time : Fri Oct 26 15:45:49 2018
Raid Level : raid1
Array Size : 495274816 (472.33 GiB 507.16 GB)
Used Dev Size : 495274816 (472.33 GiB 507.16 GB)
Raid Devices : 1
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Wed Apr 28 15:35:04 2021
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : SynHome:2 (local to host SynHome)
UUID : bf5d1657:09009110:465ee7eb:16143369
Events : 105362
Number Major Minor RaidDevice State
1 8 5 0 active sync /dev/sda5
Next part is to grow the Storage Pool so it uses the whole 1 TB of the disk. Here the issue was that the partition created by DSM only was ~500GB (to match the old disk). parted to the rescue:
root@Synology:/# parted /dev/sda
GNU Parted 3.2
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p
p
Model: Seagate IronWolf ZA1000N (scsi)
Disk /dev/sda: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
1 1049kB 2551MB 2550MB primary raid
2 2551MB 4699MB 2147MB primary raid
3 4832MB 1000GB 995GB extended lba
5 4840MB 512GB 507GB logical raid
(parted) resizepart
resizepart
Partition number? 5
5
End? [512GB]? 1000GB
1000GB
(parted) print
print
Model: Seagate IronWolf ZA1000N (scsi)
Disk /dev/sda: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
1 1049kB 2551MB 2550MB primary raid
2 2551MB 4699MB 2147MB primary raid
3 4832MB 1000GB 995GB extended lba
5 4840MB 1000GB 995GB logical raid
(parted) quit
quit
Information: You may need to update /etc/fstab.
Magics made in DSM (grow Storage Pool).
Result:
root@Synology:/# mdadm --detail /dev/md2
/dev/md2:
Version : 1.2
Creation Time : Fri Oct 26 15:45:49 2018
Raid Level : raid1
Array Size : 971834816 (926.81 GiB 995.16 GB)
Used Dev Size : 971834816 (926.81 GiB 995.16 GB)
Raid Devices : 1
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Wed Apr 28 15:59:59 2021
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : SynHome:2 (local to host SynHome)
UUID : bf5d1657:09009110:465ee7eb:16143369
Events : 105365
Number Major Minor RaidDevice State
1 8 5 0 active sync /dev/sda5
Final stage
md detail:
root@Synology:/# mdadm --detail /dev/md*
/dev/md0:
Version : 0.90
Creation Time : Sat Jan 7 19:55:24 2017
Raid Level : raid1
Array Size : 2490176 (2.37 GiB 2.55 GB)
Used Dev Size : 2490176 (2.37 GiB 2.55 GB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Thu Apr 29 09:27:09 2021
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : faaf8e9e:d3c4d9b3:3017a5a8:c86610be
Events : 0.1581285
Number Major Minor RaidDevice State
0 8 17 0 active sync /dev/sdb1
1 8 1 1 active sync /dev/sda1
/dev/md1:
Version : 0.90
Creation Time : Wed Apr 28 15:09:35 2021
Raid Level : raid1
Array Size : 2097088 (2047.94 MiB 2147.42 MB)
Used Dev Size : 2097088 (2047.94 MiB 2147.42 MB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Thu Apr 29 09:10:54 2021
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : 74eedd98:b2299432:c03470a7:6e080e63 (local to host SynHome)
Events : 0.2
Number Major Minor RaidDevice State
0 8 2 0 active sync /dev/sda2
1 8 18 1 active sync /dev/sdb2
/dev/md2:
Version : 1.2
Creation Time : Fri Oct 26 15:45:49 2018
Raid Level : raid1
Array Size : 971834816 (926.81 GiB 995.16 GB)
Used Dev Size : 971834816 (926.81 GiB 995.16 GB)
Raid Devices : 1
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Thu Apr 29 09:27:09 2021
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : SynHome:2 (local to host SynHome)
UUID : bf5d1657:09009110:465ee7eb:16143369
Events : 105365
Number Major Minor RaidDevice State
1 8 5 0 active sync /dev/sda5
/dev/md3:
Version : 1.2
Creation Time : Sun Jan 13 12:30:57 2019
Raid Level : raid1
Array Size : 11714063360 (11171.40 GiB 11995.20 GB)
Used Dev Size : 11714063360 (11171.40 GiB 11995.20 GB)
Raid Devices : 1
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Thu Apr 29 09:08:37 2021
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : SynHome:2 (local to host SynHome)
UUID : 6ffcf44d:8e2b976b:97d1189f:883f3f08
Events : 82
Number Major Minor RaidDevice State
0 8 19 0 active sync /dev/sdb3
Volume groups:
root@Synology:/# vgdisplay
--- Volume group ---
VG Name vg1
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 6
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 1
Max PV 0
Cur PV 1
Act PV 1
VG Size 926.81 GiB
PE Size 4.00 MiB
Total PE 237264
Alloc PE / Size 237059 / 926.01 GiB
Free PE / Size 205 / 820.00 MiB
VG UUID ijkBYn-GVFa-jBoI-vbnW-i3Du-OzQs-gbOhrH
LVM backup.
# Generated by LVM2 version 2.02.132(2)-git (2015-09-22): Thu Apr 29 09:35:38 2021
contents = "Text Format Volume Group"
version = 1
description = "Created *after* executing 'vgcfgbackup'"
creation_host = "Synology" # Linux SynHome 3.10.105 #25426 SMP Tue May 12 04:44:40 CST 2020 x86_64
creation_time = 1619681738 # Thu Apr 29 09:35:38 2021
vg1 {
id = "ijkBYn-GVFa-jBoI-vbnW-i3Du-OzQs-gbOhrH"
seqno = 6
format = "lvm2" # informational
status = ["RESIZEABLE", "READ", "WRITE"]
flags = []
extent_size = 8192 # 4 Megabytes
max_lv = 0
max_pv = 0
metadata_copies = 0
physical_volumes {
pv0 {
id = "qOE9fN-udnH-G5de-YlgN-XAAq-WtO3-MDdePc"
device = "/dev/md2" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 1943668480 # 926.813 Gigabytes
pe_start = 1152
pe_count = 237264 # 926.812 Gigabytes
}
}
logical_volumes {
syno_vg_reserved_area {
id = "pWpvXH-u22k-5cpX-geom-byeF-REek-MRWlPn"
status = ["READ", "WRITE", "VISIBLE"]
flags = []
segment_count = 1
segment1 {
start_extent = 0
extent_count = 3 # 12 Megabytes
type = "striped"
stripe_count = 1 # linear
stripes = [
"pv0", 0
]
}
}
volume_1 {
id = "UD1bl0-ZzXF-Djf9-tJKi-02gT-fzP4-N19VKU"
status = ["READ", "WRITE", "VISIBLE"]
flags = []
segment_count = 1
segment1 {
start_extent = 0
extent_count = 237056 # 926 Gigabytes
type = "striped"
stripe_count = 1 # linear
stripes = [
"pv0", 3
]
}
}
}
}