I’m testing duplicacy to backup a repository which has been mounted read-only and was surprised to find that even when specifying a pref-dir at a rw mount point duplicacy still wanted to create a .duplicacy file in the repository itself. Is there any way to backup a read-only repository? Is there a compelling reason why duplicacy needs to make modifications to the repository in order to back it up? I’d be happy to make a github issue with this feature request if it makes sense.
I think only the init command needs the write access. Once the .duplicacy file has been created the backup command can run with a read-only mount.
There is a feature request to allow every command to take a pref-dir argument: https://github.com/gilbertchen/duplicacy/issues/148
I missed that issue in my search, it fits my case perfectly. Even though init takes -pref-dir as an argument it still needs to create a .duplicacy file in the repository directory. I could remount the directory rw to allow the file to be created, but I don’t want the backup program changing the directory to be backed up at all.
I was in the same boat. I created an empty directory d for duplicacy and used nullfs (like bind mounts but for FreeBSD) to pull in the directories I want to back up underneath.