1) Sorry I don't know; I just use del volh type=dbb todate= and it works
fine.
Remember you CAN"T delete the most recent DB backup.

If you want to do your FILE backups in parallel with TAPE dbb backups, you
can change one of them to DBSNAPSHOT instead of DBBACKUP, that might make it
easier to manage them separately.

2) The DSMSERV RESTORE DB command is described in detail in the ADMIN
reference.  It's in a separate section in the back, so check the index for
DSMSERV RESTORE DB.

If you are restoring on the existing system and the VOLUMEHISTORY file is
intact, you don't have to specify the .dbb filename at all; TSM will find
the DEVCLASS name and .dbb filename in your volhistory file and use it
automagically when you run the DSMSERV RESTORE DB command (that's what the
volhistory file is for!).

If you are restoring in an offsite disaster recovery situation or for some
other reason don't want to rely on the information in the VOLUMEHISTORY
file, you can specify the .dbb filename.  There is really no difference in
using the .dbb files for restore than if you were using tape volumes.
Anywhere you would use a tape volser, you just substitute the .dbb filename
as the volume name, for example:

dsmserv restore db volume=d:\pathname\filename.dbb   devclass=dbfile
commit=see doc for requirements