HI,

  1. What type of drives are mt0 and mt1?
       a. is it possible that these drives are offline at the library?

  2. Does and "show library" issued from the dsmadmc client show these drives
as offline?
       a. If they show up as online, then perhaps the problem lies in the media
changer (if this is a library), or in the hw itself.
       b. If they do show up as offline, then somehow ADSM has lost contact
with these drives (maybe the scsi id changed on the drives).

  3. I suggest trying to "delete drive lib-name drive-name"  and then redefine
them with "define drive libname drivename device=/dev/mt# element=#"

Regards,  Tricia Jiang