External hard drive attached to Synology NAS failed

Synology
1

I have an 18 TB Western Digital “My Book” attached to my Synology NAS for backups. USB backup tasks are assigned to each of the shared folders on the NAS, with some running every day and others running weekly. (None are scheduled to overlap.)

Everything was going fine for over a month, then I noticed tonight that one folder backup scheduled for earlier today failed. (Subsequent to that, a backup task for a different folder succeeded.)

After I noticed that, I tried to manually re-run the failed task, but it failed again. A few minutes later, I got a notification on the NAS that the external drive “is now read-only”. I tried to view the external drive (usbshare1) in windows, but most of the folders are missing, including the one that was successfully backed up earlier today.

How/why would a drive randomly “become read-only”?

2

BTW, the error from the USB Copy backup task was “-10 (File/folder operation error)”.

3

Hmm… I disconnected the external drive and plugged it in directly to my laptop.

Now all the folders are appearing in Windows Explorer, and I am able to add a file, so it is not “read-only” as far as my laptop is concerned.

I didn’t mention earlier that all my USB Copy backups are of the Incremental type. The one movie (.mkv file) that I added recently that should have been backed up in today’s failed task is indeed not in the target folder. Everything else seems fine.

I’m not sure what to do next. The folders are physically on the drive, but are not shown when that drive is attached to the NAS as the usbshare1 external drive.

4

I’ve had it before that a hyperbackup task finds an error when it does a scheduled backup integrity check. It then marks that particular backup as read only.

Because of this I allocate hyperbackup tasks individually to each shared folder - six folders, six separate tasks. Once one is read only, you have to start again with a new hyperbackup task and if you want to keep your old backups for versioning reasons, you’re now going to be using twice as much space because you can’t delete that either.

If you’re not bothered about versions I would format the drive and start again with a very long backup.