Moving to a new laptop recently, I transferred files from my old laptop using Duplicity backups (though I now backup the new machine with Restic). Everything worked fine, except that most of the last year’s worth of locally stored Thunderbird emails are missing. I tried restoring from several backup dates aside from the most recent but still had no luck.
I decided I would try copying the Thunderbird files themselves (not the Duplicity backups) to the new laptop, but then the old laptop failed to boot. While I hope eventually to either repair the old laptop or remove its disk and mount it on my new laptop, I’m not in a position to do so now.
Has anyone else had a similar problem? Could it be that Duplicity backups of Thunderbird files are somehow incomplete? Might Restic have the same problem? Any hints as to how I might recover the lost emails without access to the old hard drive?
I also moved to Restic with the newer version of Deja Dup. I have just restored my Thunderbird whole directory and it looks fine.
I guess Duplicity backups should not depend on Deja Dup that is just a front end, so maybe you should look for Duplicity own documentation on how to recover backups. I am no expert but in my understanding the problem is Duplicity incremental backups are chained one to the other so if one fails, the following backups fail too. That is one of the resons for the change to Restic that should be more resilient.
The problem you are having happens to everybody soon or later. The nightmare of the failing backup that you discover right when you need it. I try to avoid that by using DejaDup for regular automated backups on GDrive and also making manual copies of the same files on an external drive (which aren’t “current” but it is better than nothing).