systemctl restart apparently aborts running snapshots

[DrDaveD]

See CVM-1504. It doesn't quite make sense because I previously noticed that a systemctl stop did not stop updates from happening. Maybe it does stop all the currently running services but doesn't stop the timers from restarting them. It may impact the implementation of stop-cvmfs-snapshots command, or maybe I can find a way to stop it more cleanly with only systemctl and can get rid of the command. Maybe doing a systemctl reload will be sufficient to start new services and that can be use at the end of add-repository instead of restart; if so then the README should be updated.

[bbockelm]

Hi Dave,

A few options exist - see man systemd.service:

• ExecStop - Provide an executable that will stop the service cleanly
• TimeoutStopSec - How long systemd should wait for the ExecStop script to finish (should be set to something non-infinite).
• If there's an obvious way to cleanup bad state, we can use a pre-script too with ExecStartPre.
• If there's a clear exit code for this state, we can utilize that to prevent automatic restarts.

Brian