I maintain an offsite backup server, to which I backup our company's main file share every night. There is a snapshot for every single day, giving access to previous copies. Users have access to the snapshots via vsftpd with an anonymous root in the snapdir for my backup volume.
At some point (specifically 2020-02-17 +/- a day - it's been a while since anyone needed to recover data fortunately), suddenly these permissions changed from 777 to 770 - i.e. within /backup/.zfs/snapshot, the directories for snapshots up to and including 2020-02-16 have permissions drwxrwxrwx backup/wheel, and 2020-02-17 and on have drwxrwx--- backup/wheel. I haven't changed any settings, and I can't seem to find what sets these permissions. Of course, chmod fails with a "read-only file system".
How can I restore permissions to these snapshot directories so that the ftp user can once again read these? I definitely don't want to add ftp to the wheel group for other permissions issues.
At some point (specifically 2020-02-17 +/- a day - it's been a while since anyone needed to recover data fortunately), suddenly these permissions changed from 777 to 770 - i.e. within /backup/.zfs/snapshot, the directories for snapshots up to and including 2020-02-16 have permissions drwxrwxrwx backup/wheel, and 2020-02-17 and on have drwxrwx--- backup/wheel. I haven't changed any settings, and I can't seem to find what sets these permissions. Of course, chmod fails with a "read-only file system".
How can I restore permissions to these snapshot directories so that the ftp user can once again read these? I definitely don't want to add ftp to the wheel group for other permissions issues.