CLIQ deleteSnapshot and createSnapshot - snapshot not really deleted?

[TMTech Tony]

I'm writing a script to be used in preprocessing for a Backup Exec job.  Briefly, the script checks to see if there snapshot for certain volumes exist and, if so, deletes them and then recreates them (to get the latest data).  It then goes about connecting to the iSCSI targets, and setting drive letters for the newly connected volumes.

The problem I'm having is that after I delete the snapshots through CLIQ and then try to recreate the snapshot (using the same name), I get the error "The snapshot with this name already exists" (error result 8000103a).  Looking at the CMC, it sure looks like the snapshot I deleted really is gone, BUT performing a getSnapshotInfo through the CLIQ shows that indeed, that snapshot is still there in the system somewhere. 

Eventually the snapshot does go away, but I haven't been able to determine yet how long that takes; and I'm worried that there's no way to predict how long it will take.

Does anyone have any information on this "feature?"  Anyone have any suggestions on how to deal with it?  I'm thinking of creating snapshots with different names each time the script is run (perhaps just incrementing a postfix like "-1", "-2", etc. up to a maximum of 3 or 4 or something).  But it sure would be nice if there was some way to force the snapshot deletion to finish or, barring that, someway to set the deleteSnapshot command to not complete until the snapshot is truly gone. Or something...

Tony

[Gediminas Vilutis · Accepted solution]

I notice similar behaviour with VSS enabled snapshots (using MS DPM). Apparently when you delete snapshot, cluster starts to commit its data to base LUN. How long it takes - not sure, depends. Why not to use in script unique snapshot names?

Gediminas

[Jess1313]

The reason you are getting the error is "technically" the snap has not deleted, the CMC removes the snap from visible view however it still takes time to actually delete the snap and flush all the data to the main volume.

You can check the status of the delete in the log file mgrclientbinmon.log available in the diagnostics section of your CMC.

[TMTech Tony]

This is essentially what I did. I change the snapshot name to end with "-1", "-2", etc. up to "-3". There's no way to create 3 snapshots in less time than the SAN flushes the deleted snapshots, so this works. Seems a little ugly, but everything I'm doing right now to automatically manage snapshots in preparation for Backup Exec is a bit ugly. :-(