HP Archive Backup System for OpenVMS Guide to Operations

Migrating from SLS/MDMS V2.X to ABS/MDMS V4.X
B.2 SLS/MDMS V2.x to ABS/MDMS V4.x Migration
B.2.3.7
Locations
Jukeboxes now have a “LOCATION” attribute, which is used in Opcom messages related to
moving volumes into and out of the jukebox. When moving volumes into a jukebox and if they
are not already available in that particular location, you will first be prompted to move them to
the jukebox location and then to the actual location. Likewise, when moving volumes out of the
jukebox, they will first be moved to the jukebox location and then to the actual location. The reason
being that it is more efficient to move all the volumes from their source (wherever they are)
to the jukebox location and then move all the volumes to the final destination.
One of the most important aspects of jukeboxes is whether you will be using the jukebox
with/without magazines. As described in the Section B.2.3.9, “Magazines”, MDMS V3 treats
magazines as a set of volumes within a physical magazine that share a common placement and
move schedule. Unlike MDMS V2, it is not necessary to relate volumes to magazines just
because they reside in a physical magazine, although you can. It is equally valid for volumes to
be moved directly and individually in and out of jukeboxes regardless of whether/not they reside
in a magazine within the jukebox. It is the preferred method when it is expected that the volumes
will be moved independently in and out of the jukebox.
If you decide to formally use magazines, you should set the jukebox usage to magazine. In addition,
if the jukebox can potentially hold multiple magazines at once (example - TL820 style
jukebox), you can optionally define a topology field that represents the physical topology of the
jukebox (towers, faces, levels and slots). If you define a topology field, Opcom messages relating
to magazines movement into and out of the jukebox will contain a magazine position in the
jukebox, rather than a start slot for the magazine. Use of topology and position are optional, but
they make it easier for operators to identify the appropriate magazine for movement.
Importing and exporting volumes (or magazines) into and out of a jukebox is replaced by a common
MOVE command, which specifies a destination parameter. The direction of movement is
determined depending on whether the destination is a jukebox, a location or a magazine. Unlike
previous versions, you can use a single command to move multiple volumes. The Opcom messages
will contain all the volumes to be moved, which have a common source and destination
location. If the jukebox supports ports or caps, all available ports and caps will be used. The
movement is flexible, in the sense you can place volumes in the ports/caps in any order when
importing, and all the ports will be used when exporting volumes. All port/cap oriented jukeboxes
support automatic reply on Opcom messages. It means that the messages need not be
acknowledged for the move to complete.
The concept of locations have been greatly expanded from SLS/MDMS V2, where a copy of
TAPESTART.COM had a single "ONSITE" location defined in the “LOC” symbol and a single
"OFFSITE" location defined in the “VAULT” symbol.
With MDMS V3, locations are now separate objects with the object names having a maximum
of 31 characters. Locations can be arranged in a hierarchy allowing them to be grouped within
other locations. For example, you can define “BOSTON_CAMPUS” as a location with
“BUILDING_1” and “BUILDING_2” located in it and “ROOM_100” and “ROOM_200”
located in “BUILDING_1”. Locations that have common roots are regarded as compatible locations
and are used for allocating drives, and volumes.
Example: When allocating a volume that is available in “ROOM_200” location , if you specify
the location as “BUILDING_1”, then the two locations are considered compatible. However, if
you had specified the location as “BUILDING_2”, then they would not be considered compatible
as “ROOM_200” is located in “BUILDING_1”.
Locations are not officially designated as “ONSITE” or “OFFSITE” as they can be both in some
cases. However, each volume and magazine have onsite and offsite location attributes that must
be set to valid location objects.
Migrating from SLS/MDMS V2.X to ABS/MDMS V4.X B–13