Snapshot Alarm is persitent

Hi,

we have setup an alarm when a snapshot is active (see attachment). Before I upgraded from 5.0 to 5.1 these alarms have been cleared automaticaly when the snapshot has been deleted. But now they are persitent and I have to clear them manually.

Is that a usual behaviour in 5.1 or my I change that ?

Is there maybe another way to define such an alarm. Because this alram is only triggered when the snapshot size increases 1GB of space.

Regards Wolfgang