For more than a year, users of certain models of Synology NAS servers have been able to use them with btrfs. However, a recent update has now made it impossible to access the files.
Update to 6.2.4 locks data
Affected by the lockdown are the DS420j, DS220j, DS418j, DS218play and DS118. It was possible to use these systems with btrfs as long as they were migrated or previously created with a btrfs-enabled NAS. However, these models do not actually support the btrfs file system. An unintended gap has been created here. By applying the update to DiskStation Manager 6.2.4, this unintentional gap has now been closed.
The problem with the whole thing is that now the data is locked. The btrfs drives that were previously working fine in the NAS can now no longer be opened. Access is no longer possible and it the file system can also not be formatted to ext4 so that the backup can be restored.
If you haven’t updated to 6.2.4 yet, but you are using a btrfs volume, you should backup your data first and then recreate the volumes with ext4. After the update, the data must then be reimported. Synology suggests users who do not have their own backup capability to use the 30-day trial version of Synology C2 to back up their data to the cloud via Hyper Backup.
Support from Synology helps
According to some reports, Synology’s support can help. If users grant support remote access to their NAS server, they can grant read and write access to the data so users can back up their data. For this, the drives must not be formatted beforehand.
Patch in the works
Synology is working on a patch that will allow users to continue accessing their files and not require support. However, if they want to create a new volume this will only work with the use of ext4. In the future there will be no more migration of btrfs volumes from btrfs enabled NAS to non btrfs enabled NAS. Synology has justified the deactivation by saying that it cannot ensure the secure operation of btrfs volumes on the NAS devices and that it has not sufficiently tested functions such as data integrity checking and snapshots, which are only offered with btrfs on Synology NASes.