I'm using Disk Staging on a Basic Disk storage unit.
My understanding was that high / low water marks did not apply to Basic disk.
I found a few threads that talk about Basic Disk storage units filling to 100% at which point any active backup jobs get paused and backups on disk that have been staged to tape get purged. once there is free space, the backup jobs continue.
I've noticed that this doesn't seem to happen on my basic disk storage units. based on some disk usage trending graphs i've looked at, they appear to reach 90% (the configured highwater mark) and then reduce to the low water mark.
I was also wondering if there is any "evidence" in the Activity Monitor or logs that I can monitor to see when images on disk get purged (after successful spooling to tape).