Growing a Synology DiskStation

I’ve got Synology’s cheapest two-bay NAS at home, and man, do I love it. But when I originally set it up, I used some spare disks I had laying around. One 1.5TB drive I used only as a Time Machine target, and another 500GB drive I used for the rest of everything else – system, apps, videos, that stuff. That’s not a ton of storage. When I got a new machine that needed its own backup, it was time to upgrade. Deciding where I wanted to end up was easy: 5TB drives are cheap these days, and drives die, so I’d get two of them and have 5TB of one-disk redundant storage. The tricky part was migrating the old system – Synology recommends that to grow a SHR volume, you swap one disk to a bigger one, let the array heal, then swap the other. This doesn’t work if your storage isn’t redundant to begin with.

The solution I came up with, in outline, was to create a backup to an external disk, swap the internal drives, then restore it. Here’s a procedure and some notes:

Before you begin: You’ll need an external drive with capacity larger than your used internal storage. You’ll also need, likely, a few days total to let the long file copy operations run.

1. Prep and backup the original system
   1. Take note of any applications you have installed from third party sources. Note those sources. You might need to check third party repo URLs in package center.
   2. Install the Hyper Backup app
   3. Create a new job. Choose local and external storage, and click next
   4. Create a backup task
      1. Pick the plugged-in external USB disk you’ll use
      2. Name the task something useful, and click next
   5. Select everything in “folders” to back up all files on the old drives
   6. Select everything in Applications.
   7. Disable the schedule
   8. “Run Now”
      At this point, the backup will begin, and will take quite a while. In my case, 14% of 1.74TB used backed up overnight, which made for a multi-day total job. That said, you can close DSM at any time and check back later by reopening the hyper backup app.
2. Swap drives
   1. When the backup completes, shut the NAS down and pull out the old drives. Put the new two in their place
   2. Reboot the NAS and follow the prompts to install DSM, as you did when you first set up the NAS. Use all the same credentials and whatnot that you did in the beginning, though most of this configuration will just get restored anyway. Just “skip” anything you can. DSM will actually automatically treat the two same-sized drives as a redundant pair without you doing anything special, so unless you have a more complicated setup with >2 bays, you probably don’t need to do anything else here.
   3. With DSM reinstalled, open Package Center and re-add any third-party package sources you used. Reinstall all the apps you backed up above (it seems reinstalling automatically sometimes simply doesn’t work). Make sure to install Hyper Backup
      1. This is mostly a note for me, at this point I had to add the unfortunately titled repo https://www.cphub.net to install DDNS Updater 2, which I use.
   4. Restart
3. Open Hyper Backup and restore the original backup to the new drives
   1. “Cancel” adding a new backup job when you open the app
   2. In the bottom left, click the “restore” button, and the “data” item
   3. “Restore from existing repository”
   4. Select “local shared folder and external storage,” and pick your destination
   5. Click “Restore system configuration” and select all
   6. Select all shared folders
   7. Select all applications
   8. Apply
   9. Watch the progress bar for hours and hours

Some notes:

For some reason, pieces of this don’t flow smoothly. As I mentioned above, the DSM setup definitely does – the out of box experience is great, and luckily everything seems to get configured as we want without any special setup. Restoring the backup doesn’t go as well. Some points:

• Reinstall all apps in the backup before trying to restore them. Theoretically, the ones with available package sources should reinstall. But in my experience, they don’t.
• Even if the restore “fails” (in my case, because of the apps), all the files probably copied fine.
• In my case, after the “failure,” I installed all apps manually and reran the restore, but with all the folders unchecked to avoid it taking days. This worked fine.
• App configurations will get restored
• Some apps don’t get scooped up at all, including Video Station, so mind those if you need to
• When I reconnected Time Machine, my backup said “never backed up before,” but after spinning for a while, it verified the full TM history and everything’s back to normal.
• A few configuration items didn’t transfer. In particular, certificates. My OpenVPN configuration transferred, but the cert it used changed, which required re-downloading the configuration package for clients. Also, all my SSL certificates (self-signed or otherwise) disappeared. This was an easy fix, since I was just using LetsEncrypt anyway.

Enjoy your new, larger NAS!