HP NonStop G-Series - Manual (Page 96)

Using TAPECATALOG DEFINE Attributes
DSM/Tape Catalog User’s Guide — 520233-008
6 - 4
TAPECATALOG DEFINE Attribute Descriptions

If OFF, tape requests do not go through DSM/TC and no cataloging takes
place. CATALOG OFF causes the TAPECATALOG DEFINE to function as a
TAPE DEFINE. If CATALOG OFF is specified, the FILECAT, VOLCAT, POOL,
COMMENT, PHYSICAL, and LOGICAL attributes are ignored. Also, with
CATALOG OFF specified, you cannot use the GEN attribute set to
relative
or +1, or the VERSION attribute set to NEW.
With CATALOG OFF, labeled tape processing is allowed only when the support
level is NOCATALOG, COMPATIBLE, or TPTMCOMPATIBLE.
CLASS class-type
specifies the type of DEFINE. When using tapes managed by DSM/TC, the CLASS
type is always TAPECATALOG and must be the first attribute given in the DEFINE.
The other attributes appear in any order after it.
COMMENT comment-text
lets optional descriptive text be entered for the tape file being cataloged. This text
is stored in the file catalog entry. It can be 1 to 80 characters long, composed of
any alphanumeric characters and the special characters permitted for tape file IDs
and tape names. It also follows the same rules regarding double quotation marks,
asterisks, and question marks used in tape file IDs and tape names. For more
information, see the DSM/Tape Catalog Operator Interface (MEDIACOM) Manual.
COMMENT is used only when USE OUT and CATALOG ON are used.
COMPRESSION { IDRC | OFF }
determines whether compression is used when writing data to a tape mounted on a
tape drive that supports selectable compression. If the selected device does not
support compression, this attribute is ignored.

IDRC specifies to use compression when writing the data.

OFF specifies no compression when writing the data.
The default is the value set by the MEDIACOM ALTER MEDIADEFS command on
the node named by AVRSYSTEM or the system named in DEVICE. If neither is
specified, the default is the local node.
DENSITY { 1600 | 6250 }
specifies the tape density in bits per inch (bpi) at which data is written on an output
open-reel tape. This value appears in the mount messages sent to the operator.
You cannot write data to a tape if you specify a density value for the tape that is
different from the tape’s existing density as known to DSM/TC. An error is sent to
the tape console and to the application, and processing does not continue until the
problem is resolved.
To avoid a tape density mismatch, HP recommends assigning a density value to a
pool with the intention of only cataloging tapes of the same density. See the ADD