Fixing a Failed Safepoint on WD MyBookLive NAS

linux network

TL;DR: If you're syncing linux computers to your NAS then creating a safepoint to an external drive, that drive needs to be linux-formatted or you'll get errors.

I recently bought a portable hard drive in order to make backups of my Western Digital MyBook Live Duo NAS. While trying to create a Safepoint using the Web UI, it chugs for 15 hours, then shows an unhelpful error. Trying to re-do or update the safepoint leads to a similarly unhelpful error:

There was an error updating your safepoint. There was an error updating your safepoint NAS_Offline_Backup on the My_Passport_07A8 share on MyBookLiveDuo.

Luckily my NAS runs linux and I can find out more! SSHing into the NAS, I can see the following in /var/log/wdalerts.log:

MyBookLiveDuo nas: warn: 1102: There was an error updating your safepoint. +;NAS_Offline_Backup;My_Passport_XXXX;MyBookLiveDuo;2;-

That's a start, but doesn't say much more than the web UI. Looking around, there's a second log file with more info at /var/log/wdnas.log:

Status: FAILED; Failed to complete rsync command to copy data - rsync failed with error, 23

That's definitely progress. Rsync is failing with error 23, which according to rsync docs is "Partial transfer due to error". Searching the web, I found a reference saying that the actual error might be:

some files/attrs were not transferred

So it looks like the root cause is mis-matched filesystems - I'm copying data from my linux laptop to the linux NAS to the windows-formatted external drive, the permissions are not making it all the way and rsync complains.If I were running windows on my laptop, the files on the NAS wouldn't have any extra permissions, and they would be happily copied to the NTFS drive without errors.

The solution for me is to reformat the portable hard drive as ext4, then try creating the safepoint.

I reformatted it by plugging the portable drive directly into my laptop, then launching GParted in Ubuntu. Make sure you select the removable drive when partitioning, or you will lose all of your data!

Once it was repartitioned, I plugged it back into the NAS, kicked off another safepoint, waited 15 hours, and got a nice "success!" message in the web UI.