Migrate non-redundant data to larger disk on Synology NAS

Question

I have a Synology DS213j using two disks I had to spare, 2TB and 1.5TB. These are nearly full so I plan to replace them. To put all data onto the new disks I just wanted to connect the old disks to my desktop computer and copy the files. But now I read that this might not be possible because of the raid, even though I didn't really use one. The disks are in a Synology Hybrid RAID (SHR), but without any data protection so I can use the full space as you can see on the screenshot.

Also all my shared folders are explicitly on a single volume as you can see here

So as far as I know SHR just causes the volumes to appear as a single logical unit in this case but does not spread any data. Am I right about this? Can I just connect the old disks to my computer and copy the data or does SHR prevent this simple approach? If so, how else could I do it? To say upfront: I don't have 3.5TB of free storage to store the data elsewhere.

Answer 1

If I grasp this Synology guide correctly, Synology Hybrid RAID is just a fancy name for Linux MDRAID coupled with Linux LVM. The filesystem is already visible on your screenshots: ext4. It’s available on virtually any maintained distributions.

The basic steps are these:

1. Connect all drives to your PC
2. Use some suitable Linux distribution (like Ubuntu), either installed or booted from a Live CD/USB
3. Install the mdadm and lvm2 packages (name may vary)
4. Run mdadm -As && vgchange -ay to start MDRAID and scan for LVM volumes
   • If, and only if, it doesn’t work with mdadm -As, use mdadm -Asf to import even damaged arrays
5. Access data either via your distributions auto-mounting mechanism or by manually mounting them
   • You can find volume names with lvs, they are typically located at /dev/<vg name>/<lv name>.

These steps should work for any kind of SHR configuration.