Define Device Class

Use this window to define a device class for storage pools.


Devclassname

Type the name of the device class to be defined in the Device class name field. The maximum length of the device class name is 30 characters.


Format

Use the Format select box to specify the recording format to be used when writing data to sequential access media.

You can choose only one selection from the list.

Default: Drive

The settings for Format are:

Drive Specifies that ADSM selects the highest format that can be supported by the sequential access drive on which a volume is mounted.
DDS1 Specifies that ADSM writes data using the DDS-1 recording format for 4mm tapes, without compression. This format results in an uncompressed cartridge capacity of 1.3GB on 60 meter tape or 2GB on 90 meter tape. This format only applies to 60 and 90 meter tapes.
DDS1C Specifies that ADSM writes data using the DDS-1 recording format for 4mm tapes, with compression enabled. This results in a cartridge capacity of approximately 1.3GB on a 60 meter tape or 2GB on a 90 meter tape. This format, however, uses the tape drive hardware compression feature, so the actual capacity may be greater, depending on the effectiveness of compression. This format only applies to 60 and 90 meter tapes.
DDS2 Specifies that ADSM writes data using the DDS-2 recording format for 4mm tapes, without compression. This format results in a cartridge capacity of 4GB on 120 meter tape. This format only applies to 120 meter tape.
DDS2C Specifies that ADSM writes data using the DDS-2 recording format for 4mm tapes, with compression. This format results in a cartridge capacity of approximately 8GB on 120 meter tape. This format, however, uses the tape drive hardware compression feature, so the actual capacity may be greater, depending on the effectiveness of compression. This format only applies to 120 meter tape.
DDS3 Specifies that ADSM writes data using the DDS-3 recording format for 4mm tapes, without compression. This format results in a cartridge capacity of 12GB on 125 meter tape. This format only applies to 125 meter tape.
DDS3C Specifies that ADSM writes data using the DDS-3 recording format for 4mm tapes, with compression. This format results in a cartridge capacity of approximately 24GB on 125 meter tape. This format, however, uses the tape drive hardware compression feature, so the actual capacity may be greater, depending on the effectiveness of compression. This format only applies to 125 meter tape.

Library

Type the name of the defined library object that contains the 4mm tape drives used by this device class in the Library field.


Mountlimit

Type the maximum number of sequential access volumes that can be simultaneously mounted for the device class in the Mountlimit field.

Default: Drives

Considerations:

The following are possible values:

Drives Specifies that every time a mount point is allocated, the number of drives defined to the library is used to calculate the true mountlimit value, (including taking into account whether each is online).
Mountlimitvalue Specifies the maximum number of drives used concurrently in this device class by ADSM. This value must never be allowed to exceed the number of drives that are defined and online in the library that services this device class.
0 The value of zero prevents new transactions from gaining access to the storage pool.

Mountretention

Type the amount of time, in minutes, to retain an idle sequential access volume before dismounting it in the Mount Retention field.

Default: 60

Considerations:


Prefix

Type the high level qualifier of the file name that the server writes into the sequential access media labels in the Prefix field. For each sequential access volume assigned to this device class, ADSM uses this prefix to create the data set name.

Default: ADSM

Considerations:


Estcapacity

Type the estimated capacity for the sequential access volumes categorized by this device class in the Estimate Capacity field. Specify an integer followed by a scale factor.

Scale factors and their meanings are:

K Kilobyte
M Megabyte
G Gigabyte

Mountwait

Type the maximum length of time, in minutes, to wait for a sequential access volume to be mounted in the Mount Wait field.

Default: 60

Considerations: