I have the problem, that my backup is flooded by mozilla's firefox' profiles. I have only one user with multiple profiles.

The thing is that firefox saves various data in sqlite files etc that just are updated. I use a rsnapshot-based backup approach: if a file has not changed it is hard-linked to the last version. So no storage is consumed. If the file on the other hand has changed it needs to be completely written to the backup. This causes the backup to increase rapidly although this is not always important data but caches etc. So I intend to exclude the temporary cached and other data from the backup.

Now I saw that the biggest block in the firefox profile folder that seems to have regular updates is the storage/default folder. Searching the internet I found this link. As far as I understand this, I can safely drop the files in the storage/default and storage/temporary folders in the backup. Firefox will recreate the content when I visit the pages again.

Is this correct? What sort of information is saved there (except for caches and temporary data)?