• It seems I found the solution: old DBBackup-tapes were marked mountable in DRM? I don`t no why. I checked offsite tapes and realized that affected tapes were offsite. I set the tapes to “vault” state by using:

move drmedia $tape rem=no tostate=vault

Immediately DRM set the tapes to vaultretrieve and now I hope getting back tapes from offsite location.

• Have the same situation with my DBBackup vols as well since we stopped vaulting DRM volumes

DEL VOLHIST TYPE=ALL TODATE=TDAY-32 
DEL VOLHIST TYPE=DBB TDATE=TODAY-8