In my environment, I keep 1 month of DAG backups in MSDP. I've had a restore request going back 3 months. Granular restores work fine for items that are in MSDP and I understand that GRT only works from disk, so I've used the Java Admin Console to duplicate most of the images from tape back into MSDP (there are a couple of tapes still offsite)
In the Java Admin Console I attempt a restore based on the date range the tape images were written; I see the DAG hiearchy and navigate down the structure and finally expand the "Database" item. This shows the list of mailboxes, I locate the one I want and click the icon to expand it and nothing happens (I expect to see a list of folders starting with "Top of Information Store")
I had this same behaviour before I duplicated the tapes back to MSDP, so not sure what's going on....
How do I query what mailboxes are in the backup images? (to check if the mailbox I want is on a tape I have duplicated or is it on a tape that is still offsite?)
As far as I understand, you cannot run GRT restores from tape. Meanign that if you duplicate image to tape and then back to MSDP, the GRT meta-information was somehow lost when it "touched" the tape. However, the Catalog still is "aware" that it was GRT backup. Bug?
Querrying for details of backed-up data in NetBackup, like which database or mailbox, went when and where is a pain. The best way is to use the BAR console, but in your case it seems it got a bit lost too.