If you are defining a device class for devices that are to be accessed through a z/OS® media server, see UPDATE DEVCLASS (Update a 3592 device class for z/OS media server).
To issue this command, you must have system privilege or unrestricted storage privilege.
>>-UPDate DEVclass--device_class_name---------------------------> >--+--------------------------+---------------------------------> '-LIBRary--=--library_name-' >--+-----------------------------+------------------------------> '-LBProtect--=--+-READWrite-+-' +-WRITEOnly-+ '-No--------' >--+---------------------------+--+------------------------+----> '-SCALECAPacity--=--+-100-+-' '-FORMAT--=--+-DRIVE---+-' +-90--+ +-3592----+ '-20--' +-3592C---+ +-3592-2--+ +-3592-2C-+ +-3592-3--+ +-3592-3C-+ +-3592-4--+ '-3592-4C-' >--+----------------------+-------------------------------------> '-ESTCAPacity--=--size-' >--+-----------------------------------+------------------------> '-PREFIX--=--+-ADSM---------------+-' '-tape_volume_prefix-' >--+----------------------------+--+-----------------------+----> '-MOUNTRetention--=--minutes-' '-MOUNTWait--=--minutes-' >--+---------------------------+--------------------------------> '-MOUNTLimit--=--+-DRIVES-+-' +-number-+ '-0------' >--+----------------------------------------------+------------>< | (1) (2) | '-------------DRIVEEncryption--=--+-ON-------+-' +-ALLOW----+ +-EXTERNAL-+ '-OFF------'
Specifies whether logical block protection is used to ensure the integrity of data stored on tape. When LBPROTECT is set to READWRITE or to WRITEONLY, the server uses this feature of the tape drive for logical block protection and generates cyclic redundancy check (CRC) protection information for each data block written on tape. The server also validates the CRC protection information when data is read from the tape.
When the LBPROTECT parameter is set to READWRITE, you do not have to specify the CRCDATA parameter in a storage pool definition because logical block protection provides better protection against data corruption.
See Technote 1634851, Additional information on the Tivoli Storage Manager LBProtect option, for an explanation about when to use the Tivoli Storage Manager LBProtect parameter.
Setting the scale capacity percentage to 100 provides maximum storage capacity. Setting it to 20 provides fastest access time.
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.
|
3592 | 300 GB | Uncompressed (basic) format |
3592C | See note 900 GB |
Compressed format |
3592-2 | 500 GB 700 GB |
Uncompressed (basic) format JA tapes Uncompressed (basic) format JB tapes |
3592-2C | 1.5 TB 2.1 TB |
Compressed format JA tapes Compressed format JB tapes |
3592–3 | 640 GB 1 TB |
Uncompressed (basic) format JA tapes Uncompressed (basic) format JB tapes |
3592–3C | 1.9 TB 3 TB |
Compressed format JA tapes Compressed format JB tapes |
3592-4 | 400 GB 1.5 TB 3.1 TB |
Uncompressed (basic) format JK tapes Uncompressed (basic) format JB tapes Uncompressed (basic) format JC tape |
3592-4C | 1.2 TB 4.4 TB 9.4 TB |
Compressed format JK tapes Compressed format JB tapes Compressed format JC tapes |
Note: If this format uses the tape-drive hardware-compression
feature, depending on the effectiveness of compression, the actual
capacity might be different from the listed value.
|
Special configurations are also required for mixing different generations of 3592 drives in 349x and ACSLS libraries. For details, see the Administrator's Guide.
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 K (kilobytes), M (megabytes), G (gigabytes), or T (terabytes). For example, ESTCAPACITY=5M specifies that the estimated capacity for a volume in this device class is 5 MB.
The smallest value that is allowed is 1 MB (that is, ESTCAPACITY=1M). To force the IBM Tivoli Storage Manager server to determine the estimated capacity for the volumes that are assigned to this device class, specify ESTCAPACITY="".
If you previously established a media label naming convention that supports your current management system, use a volume prefix that conforms to your naming conventions.
An example of a tape volume data set name that uses 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, setting this parameter to a low value (for example, two minutes) enhances 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.
Updating this parameter affects empty volumes only. If a filling volume was previously encrypted or is unencrypted, and you update the DRIVEENCRYPTION parameter, the volume maintains its original encrypted or unencrypted status. The filling volume also maintains its original key-management status.