mirror of
https://github.com/007revad/Synology_Recover_Data.git
synced 2026-04-25 08:45:53 +03:00
[GH-ISSUE #37] can't read superblock #3
Labels
No labels
pull-request
No milestone
No project
No assignees
1 participant
Notifications
Due date
No due date set.
Dependencies
No dependencies set.
Reference
starred/Synology_Recover_Data#3
Loading…
Add table
Add a link
Reference in a new issue
No description provided.
Delete branch "%!s()"
Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?
Originally created by @nicimar on GitHub (Nov 11, 2025).
Original GitHub issue: https://github.com/007revad/Synology_Recover_Data/issues/37
Hi,
I have a single HDD from my DS218+ which was SHR/volume1 btrfs and I tried to mount in ubuntu. It was the only HDD in this SHR and was replaced by a bigger one. It is mounted via your script but shows empty and it shows "can't read superblock" error while mounting. I thought this problem would only be present with an actual ubuntu version. I tried Ubuntu 19.10 (Eoan Ermine) as well as Ubuntu 18.04 which is recommended by Synology. Both show the same problem. After booting from USB stick I had to install mdadm via apt-get install before running your script as it was not installed by the script automatically. I guess it installed a newer version of mdadm causing the error with superblock.
root@ubuntu:/home/ubuntu# sudo /home/ubuntu/syno_recover_data.sh
Synology_Recover_Data v1.1.13
Assembling your Synology drives
mdadm: No arrays found in config file or automatically
1 logical volume(s) in volume group "vg1000" now active
Type yes if you are ready to mount /dev/vg1000/lv
to /home/ubuntu/vg1000
yes
Creating mount point folder(s)
Mounting volume(s)
mount: /home/ubuntu/vg1000: can't read superblock on /dev/mapper/vg1000-lv.
The volume is now mounted as read only.
You can now recover your data from:
PVS/VGS/LVS show the following:
root@ubuntu:/# pvs
PV VG Fmt Attr PSize PFree
/dev/md127 vg1000 lvm2 a-- 7.27t 0
root@ubuntu:/# vgs
VG #PV #LV #SN Attr VSize VFree
vg1000 1 1 0 wz--n- 7.27t 0
root@ubuntu:/# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv vg1000 -wi-a----- 7.27t
@007revad commented on GitHub (Nov 12, 2025):
The "can't read superblock" error is caused by your Ubuntu having the latest mdadm which does not support DSM's superblock location.
The script should have set /etc/apt/sources.list to install an older version of mdadm. Maybe the script skipped installing the needed version of mdadm because your Ubuntu boot drive already had mdadm installed.
In Ubuntu try:
@nicimar commented on GitHub (Nov 13, 2025):
after booting ubuntu from stick I got an error when the script starts:
root@ubuntu:~# sudo -i /home/ubuntu/syno_recover_data.sh
Synology_Recover_Data v1.1.13
/home/ubuntu/syno_recover_data.sh: line 134: curl: command not found
ERROR mdadm not installed!
the script did not install mdadm automatically but the sources.list was adopted by your script:
deb cdrom:[Ubuntu 19.10 Eoan Ermine - Release amd64 (20191017)]/ eoan main restricted
deb http://old-releases.ubuntu.com/ubuntu/ eoan main restricted
deb http://old-releases.ubuntu.com/ubuntu/ eoan-security main restricted
deb http://old-releases.ubuntu.com/ubuntu/ eoan-updates main restricted
so I did apt update und apt install curl mdadm
mdadm version 4.1 was installed:
root@ubuntu:~# mdadm --version
mdadm - v4.1 – 2018-10-01
Is this a version which should able to read the superblock?
I repeated everything with a freshly installed usb boot stick and got the same behavior.
mount: /home/ubuntu/vg1000: can't read superblock on /dev/mapper/vg1000-lv.
My NAS is a Synolgy DS218+ with DSM 7.2.2 Update 4.
@007revad commented on GitHub (Nov 14, 2025):
I can't find my Ubuntu USB boot drive (after moving recently).
But I do know that mdadm v4.4 is the latest. Both v4.4 and v4.3 are from 2024. DSM 6.2.4 and 7.3.1 use madam v3.4
Try uninstalling mdadm then
apt install mdadm=<version_number>.@nicimar commented on GitHub (Nov 17, 2025):
Thx for the reply. I did get it working with version mdadm 4.1 to read the superblock and mount the volume after I changed the USB - SATA Adapter. But now I get E/A errors and it is not possible to copy some part of the data. Anyway, I decided to reinstall the drive into the NAS to copy the data. I guess it is maybe a better idea not to use Btrfs Volumes on Synology NAS when it is so difficult to mount it with a Linux distribution. I think Synology should provide a simple solution e.g. a full working ubuntu ISO for the case if emergency or at least make it clear in the documentation. Thx for your help and your work on the scripts.