I'm using dsync for a regular backup. The backup system flocks so that two cannot run at the same time, which is generally a good thing. The problem is that it seems like dsync sometimes goes off into the weeds and never comes back, leaving a process running and doing nothing forever, hogging the lock and causing my backups never to run again. I just finally figured out that was what was causing the backups not to run on this system was this process:
root 17836 0.0 0.0 40888 1600 ? S 2012 0:00 ssh -i /root/.ssh/backmaildir_id_rsa backmaildir@arg /usr/bin/dsync -u foobar server
yeah, that has been running since 2012 :(
root:/tmp# strace -p 17836 Process 17836 attached - interrupt to quit select(8, [4], [], NULL, NULL
very exciting...
There doesn't seem to be a timeout in dsync, but perhaps there should be? At this point my only option is to write a cronjob that will look for dsync processes that are over a certain amount of time old and then kill them, after I do that I will need to take a shower because that is a very dirty solution :P