[Box Backup] Suggested change in behaviour

[Ben Summers]

Imagine this scenario. You have a single partition on a hard drive, 
mounted as /home. This drive fails, the server reboots, but fails to 
pass fsck checks as much is unreadable. You modify /etc/fstab so it 
isn't mounted, and reboot. The machine comes up.

Unfortunately, you forgot to disable bbackupd running on boot, which 
you've got running in lazy mode. It runs, does it's initial scan, and 
marks everything in this partition as deleted.

This is unlikely to help the situation much, and incidentally, has just 
happened to me. (Fortunately, I have "undelete" technology hidden in 
the server, and have just written a bit of code to allow access to it 
via bbackupquery, so it's not a calamity - even if it has also 
undeleted files which were deleted by the users before the partition 
vanished.)

I propose a slight change in behaviour which may go some way towards 
resolving this problem, but I wonder if it will cause any other issues.

* If bbackupd finds that the root of a Location (as specified in 
bbackupd.conf) contains no files or directories, it

    - will log a message "Backup location /x is empty, not changing 
store" at level LOG_ERR

    - will not modify the relevant location on the server

Can anyone see any situation where this might cause problems? This will 
only be triggered if there's absolutely nothing to back up in a 
location.

Thanks,

Ben