Use the 4MM device class when you are using 4 mm tape devices.
To issue this command, you must have system privilege or unrestricted storage privilege.
>>-DEFine DEVclass--device_class_name---------------------------> >--LIBRary--=--library_name--DEVType--=--4MM--------------------> .-FORMAT--=--DRIVE-----. >--+----------------------+--+----------------------+-----------> '-FORMAT--=--+-DRIVE-+-' '-ESTCAPacity--=--size-' +-DDS1--+ +-DDS1C-+ +-DDS2--+ +-DDS2C-+ +-DDS3--+ +-DDS3C-+ +-DDS4--+ +-DDS4C-+ +-DDS5--+ +-DDS5C-+ +-DDS6--+ '-DDS6C-' .-PREFIX--=--ADSM-------------------. >--+-----------------------------------+------------------------> '-PREFIX--=--+-ADSM---------------+-' '-tape_volume_prefix-' .-MOUNTWait--=--60------. .-MOUNTRetention--=--60------. >--+-----------------------+--+----------------------------+----> '-MOUNTWait--=--minutes-' '-MOUNTRetention--=--minutes-' .-MOUNTLimit--=--DRIVES-----. >--+---------------------------+------------------------------->< '-MOUNTLimit--=--+-DRIVES-+-' +-number-+ '-0------'
If the drives are in a library that includes drives of different tape technology, do not use the DRIVE value. Use the specific format that the drives use.
Format | Estimated Capacity | Description |
---|---|---|
DRIVE | – | The server selects the highest format
that is supported by the drive on which a volume is mounted. Attention: Avoid specifying DRIVE when a mixture of drives is
used within the same library. For example, do not use this option
for a library that contains some drives that support recording formats
superior to other drives.
|
DDS1 | 2.6 GB (60 meter) 4.0 GB (90 meter) |
Uncompressed format, applies only to 60-meter and 90-meter tapes |
DDS1C | See note 1.3 GB (60 meter) 2.0 GB (90 meter) |
Compressed format, applies only to 60-meter and 90-meter tapes |
DDS2 | 4.0 GB | Uncompressed format, applies only to 120-meter tapes |
DDS2C | See note 8.0 GB |
Compressed format, applies only to 120-meter tapes |
DDS3 | 12.0 GB | Uncompressed format, applies only to 125-meter tapes |
DDS3C | See note 24.0 GB |
Compressed format, applies only to 125-meter tapes |
DDS4 | 20.0 GB | Uncompressed format, applies only to 150-meter tapes |
DDS4C | See note 40.0 GB |
Compressed format, applies only to 150-meter tapes |
DDS5 | 36 GB | Uncompressed format, when using DAT 72 media |
DDS5C | See note 72 GB |
Compressed format, when using DAT 72 media |
DDS6 | 80 GB | Uncompressed format, when using DAT 160 media |
DDS6C | See note 160 GB |
Compressed format, when using DAT 160 media |
Note: If this format uses the tape drive hardware compression
feature, depending on the effectiveness of compression, the actual
capacity might be greater than the listed value.
|
You can specify this parameter if the default estimated capacity for the device class is inaccurate due to compression of data.
You must specify this value as an integer followed by one of the following unit indicators: K (kilobytes), M (megabytes), G (gigabytes), or T (terabytes). The smallest value that is accepted is 1 MB (ESTCAPACITY=1M).
For example, specify that the estimated capacity is 9 GB with the parameter ESTCAPACITY=9G.
If you have a naming convention for media labels to support your current management system, use a volume prefix that conforms to your naming conventions.
AB.CD2.E
An example of a tape volume data set name using the default prefix is ADSM.BFS.
This parameter can improve response time for sequential access media mounts by leaving previously mounted volumes online.
However, for EXTERNAL library types (that is, a library that is managed by an external media management system), set this parameter to a low value (for example, two minutes) to enhance device sharing between applications.
If you plan to use the simultaneous-write function, ensure that sufficient drives are available for the write operation. If the number of drives needed for a simultaneous-write operation is greater than the value of the MOUNTLIMIT parameter for a device class, the transaction fails.