Andy et al.,

Some time ago, I cast some doubt on the functionning of ADSM database
recovery using a mirrored copy.  I'm happy to say that the error we
encountered was due to a recently-introduced bug in the external tape-
manager routine we are using.  After fixing that, the recovery works if
one takes the proper precautions (such as reformatting the zone where the
defective copy should be re-written).  In general, the recipe given on p.
299 of the Administrator's Guide is correct.

There does seem to be a bug, tho, in the external-tape manager use when
doing a DB restore by the

   dsmserv restore db

command.  In this case, dsmserv does not recognize the external library
type and bombs out because no drive is defined for the library.  In fact,
one does not define drives for an external library.  The workaround is to
edit the device configuration backup file to:

change the devclass definition to associate the tape to a manual library

add a drive definition with the real (/dev/rmt_nnnn) name of the drive
used for the recovery.

Aside from that, the external-library method works well.  It allows
sharing of drives with other applications (assuming you have the software
necessary to do the allocations) and is far superior to the
message-output-only interface available by the dsmc -mount option.

Thanks, Andy, for your suggestions.

Regards, John

--------------------------------------------------------------
John O'Neall                         e-mail:  jon AT in2p3 DOT fr
John O'Neall                         e-mail:  jon AT in2p3 DOT fr
Centre de Calcul de l'IN2P3          phone:   (33) 78 93 08 80
Villeurbanne, France                 fax:     (33) 78 94 30 54