For some unknown reason a customer's backup job hung. A ps axuww looked like this after a failed kill 3150 attempt:
3150 ? Z 0:00 [mysqldump] <defunct>
There was no other way of getting rid of that other than a reboot. It didn't help, though. It automatically re-started the backup job and did the same thing again.
All customer's services were disabled, there was Suspend domain until backup task is completed -setting enabled. At that point I was really screwed. The backup job turned undead and all customer's services were out of action. Nice going! The message that was given from Parallels Panel at control panel was: "The subscription is temporarily suspended until the backup or restore process is complete".
Parallels forums had an article about unsuspending a domain. I did the same thing for a subscription. Apparently at the time of writing in Plesk 9, there were no subscriptions. So I ran this:
/usr/local/psa/bin/subscription -u customer's domain name here.com -status enabled
It helped! It un-suspended the services. The backup is not working yet, but the services were running again. I need to further investigate the backup issue and get back about that.