Esoteric error message when backup media is missing

[Xavier Johnson]

When Deja Dup's backup location is set to external media (like an external HDD), trying to perform a backup when the backup location is disconnected or unavailable (like the HDD being unplugged) fails with a cryptic message:

"Error creating directory /run/media: Permission denied"

This message implies that like Deja Dup/Duplicity attempts to create the directory of its backup location if it doesn't exist, and fails to do so because of DAC. If that is what actually happens, then this error message technically makes sense. But, it still doesn't mention the real issue, which is that the backup location simply isn't present.

A better message could be:

"Error: backup location <path> not found or could not be created"

Better yet, perhaps there should also be an option for Deja Dup/Duplicity to fail immediately when its backup location does not exist, instead of trying to create it.

LSB Version: :core-4.1-amd64:core-4.1-noarch
RPM versions: deja-dup-36.3-1.fc26.x86_64
                duplicity-0.7.14-2.fc26.x86_64

[Michael Terry (mterry)]

I agree that's a weak error message. I was testing with external drives and didn't reproduce this. But I'm testing on Ubuntu. I wonder if the way Fedora mounts drives is conflicting with what Deja Dup expects...

[Xavier Johnson (mr-johnson22)]

The same error occurs whether the backup is started manually or automatically. It also occurs when trying to restore from the backup location (if it is disconnected, of course).

If it helps, here is the output of 'ls -ld' on my backup directory:

drwxrwxrwx. 1 mr_johnson22 mr_johnson22 4096 <date> <time> '/run/media/mr_johnson22/<folder_name>/'

The kind of backup media used probably doesn't make a difference, as the same problem happens whether I use an external NTFS hard drive vs a FAT16 SD card as my backup locations (and they both get mounted at /run/media/<username>/).

[Xavier Johnson (mr-johnson22)]

Oh, I figured it out: I had set my storage location to "Local Folder", setting it to the path to the backup directory on the external drive. When I change the storage location to be the drop-down box's entry for my external drive and type in the name of my backup folder, the "Error creating directory" error gets replaced by the kind of error I wanted to see: "Storage location not available - Waiting for <media> to become connected..."

This is good news, but it would still be nice if the error for a missing "Local Folder" storage location could be made more clear, since it's not all that unlikely for someone to pick a "local" folder that is actually on external media (since setting a "Local Folder" opens a file browser to let you pick the folder you want to use, instead of having to type in a folder name or path), and getting clearer error messages for that setup would go a long way in improving usability.

[Michael Terry (mterry)]

I believe this is fixed in 42.2 — selecting a drive via Local Folder should switch you to a mountable drive setup.