DEFINE DEVCLASS (Define an ECARTRIDGE device class for z/OS media server)

Privilege class

To issue this command, you must have system privilege or unrestricted storage privilege.

Parameters

device_class_name (Required)

Specifies the name of the device class to be defined. The maximum length of the device class name is 30 characters.

LIBRary (Required)

Specifies the name of a library that was defined with the LIBTYPE=ZOSMEDIA parameter. The library and the tape drives that can be used by this device class are controlled by the z/OS media server.

For information about defining a library, see the DEFINE LIBRARY command.

DEVType=ECARTridge (Required)

Specifies that the ECARTRIDGE device type is assigned to the device class. The ECARTRIDGE device type is for StorageTek drives such as the StorageTek T9840 or T10000.

FORMAT

Specifies the recording format to be used when data is written to sequential access media. This parameter is optional.

See the following table for the recording formats.

Table 1. Recording formats for ECARTRIDGE tapes

Format	Estimated Capacity	Description
DRIVE	-	The server selects the highest format that is supported by the drive on which a volume is mounted. DRIVE is the default value. 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 containing some drives that support recording formats superior to other drives.
T9840C	40 GB	Uncompressed T9840C format, using a StorageTek 9840 cartridge
T9840C-C	80 GB	Compressed T9840C format, using a StorageTek 9840 cartridge
T9840D	75 GB	Uncompressed T9840D format, using a StorageTek 9840 cartridge
T9840D-C	150 GB	Compressed T9840D format, using a StorageTek 9840 cartridge
T10000A	500 GB	Uncompressed T10000A format, using a StorageTek T10000 cartridge
T10000A-C	1 TB	Compressed T10000A format, using a StorageTek T10000 cartridge
T10000B	1 TB	Uncompressed T10000B format, using an Oracle StorageTek T10000 cartridge
T10000B-C	2 TB	Compressed T10000B format, using an Oracle StorageTek T10000 cartridge
T10000C	5 TB	Uncompressed T10000C format, using an Oracle StorageTek T10000 T2 cartridge
T10000C-C	10 TB	Compressed T10000C format, using an Oracle StorageTek T10000 T2 cartridge
T10000D	8 TB	Uncompressed T10000D format, using an Oracle StorageTek T10000 T2 cartridge
T10000D-C	15 TB	Compressed T10000D format, using an Oracle StorageTek T10000 T2 cartridge
Note: Some formats use a compression feature of the tape drive hardware. Depending on the effectiveness of compression, the actual capacity might be double or more than the listed value. T10000A drives can read and write the T10000A format only. T10000B drives can read, but cannot write, the T10000A format. T10000C drives can read, but cannot write, the T10000A and T10000B formats. T10000D drives can read, but cannot write, the T10000A, T10000B, and T10000C formats.

ESTCAPacity

Specifies the estimated capacity for the volumes that are assigned to this device class. This parameter is optional. The default estimated capacity is 9 GB.

You can specify this parameter if the default estimated capacity for the device class is inaccurate because of compression of data. The value does not determine the amount of data stored on the volume. The server uses the value to estimate the usage before a volume is filled. After a volume is full, the actual amount of data stored on the tape is used for the usage calculation.

Specify the value as an integer with one of the following unit indicators: K (KB), M (MB), G (GB), or T (TB). For example, specify that the estimated capacity is 9 GB with the parameter ESTCAPACITY=9G. The smallest value that is accepted is 100 KB (ESTCAPACITY=100K).

PREFIX

Specifies the high-level qualifier of the data set name that the server writes into the sequential access media labels. For each sequential access volume assigned to this device class, the server uses this prefix to create the data set name. This parameter is optional. The default value is ADSM. The maximum length of this prefix is 8 characters.

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.

Values that are specified for this parameter must meet the following conditions:

• The value is to be made up of qualifiers, which can be a maximum of eight characters including periods. For example, the following value is acceptable:

       AB.CD2.E

• The qualifiers must be separated by a single period.
• The first letter of each qualifier must be alphabetic or national (@,#,$), followed by alphabetic, national, hyphen, or numeric characters.

An example of a tape volume data set name using the default prefix is ADSM.BFS.

MOUNTRetention

Specifies the number of minutes that an idle tape volume is retained before it is dismounted. The time span for mount retention begins after the idle timeout period has expired. This parameter is optional. The default value is 60 minutes. Specify a number 0 - 9999.

This parameter can improve response time for sequential access media mounts by leaving previously mounted volumes online.

MOUNTWait

Specifies the maximum number of minutes that the z/OS media server waits for a volume mount. If the mount request is not satisfied within the specified time, the mount request fails. If a device is successfully allocated and the device-open request does not complete within the specified time, the device-open request ends and the mount request fails.

This parameter is optional. The default value is 60. Specify a number, 1 - 9999.

Restriction: If the library that is associated with this device class is external (LIBTYPE=EXTERNAL), do not specify the MOUNTWAIT parameter.

MOUNTLimit

Specifies the maximum number of sequential access volumes that can be simultaneously mounted for the device class. This parameter is optional. The default is 2.

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.

You can specify one of the following values:

DRIVES

Specifies that every time a mount point is allocated, the number of drives that are defined and online in the library is used to calculate the true value.

number

Specifies the maximum number of drives in this device class that are used concurrently by the server. This value must never exceed the number of drives that are defined and online in the library that services this device class. You can specify a number, 0 - 4096.

0 (zero)

Specifies that no new transactions can gain access to the storage pool.

COMPression

Specifies whether file compression is used for this device class. This parameter is optional. The default value is YES.

You can specify one of the following values:

Yes

Specifies that the data for each tape volume is compressed.

No

Specifies that the data for each tape volume is not compressed.

EXPiration

Specifies the expiration date that is placed on the tape labels for this device class. This parameter is optional. There is no default value.

Specify the date when the server no longer requires the tape. The server does not use this information, but this information is passed to the z/OS media server for use by z/OS or tape management systems.

Specify the expiration date using the format, yyyyddd (four digits for the year and three digits for the day). For example, January 7, 2014 is specified as 2014007 (the seventh day of year 2014).

If you specify the EXPIRATION parameter, you cannot specify the RETENTION parameter.

RETention

Specifies the number of days to retain the tape. This parameter is optional.

Specify the number of days (1 - 9999) that the server is expected to use the tape. The server does not use this information, but this information is passed to the z/OS media server for use by z/OS or tape management systems.

If you specify the RETENTION parameter, you cannot specify the EXPIRATION parameter.

PROtection

Specifies whether the RACF® program, if installed, protects volumes that are assigned to this device class. If protection is provided, RACF profiles are created when volumes are first used. This parameter is optional. The default value is NO. You can specify one of the following values:

No

Specifies that the RACF program does not protect volumes that are assigned to this device class.

Yes

Specifies that the RACF program protects volumes that are assigned to this device class. RACF profiles are created for volumes when the server first uses the volumes, but the profiles are not deleted when volumes are deleted from the server. Profiles must be manually deleted.

Tip: If sensitive data is stored on volumes that are assigned to this device class, use PROTECTION=YES and manually delete RACF profiles only after tape volumes have been erased.

The profiles that are created for volumes depend on the system RACF settings. The protection that is provided is the same as using PROTECT=YES in JCL. If the RACF program is active and both TAPEVOL and TAPEDSN are inactive, allocation of tapes fails.

Automatic

Specifies that the RACF program protects volumes that are assigned to this device class. RACF profiles are created for volumes when the server first uses the volumes. RACF profiles are deleted when volumes are deleted from the server.

The profiles that are created for volumes depend on the system RACF settings. The protection that is provided is the same as using PROTECT=YES in JCL. If the RACF program is active and both TAPEVOL and TAPEDSN are inactive, allocation of tapes fails.

Important: If you specify PROTECTION=AUTOMATIC, when a volume is deleted, its RACF profile is deleted. The volume therefore is no longer protected by the RACF program. The data on these volumes can be accessed by other users.

If you specify PROTECTION=AUTOMATIC, the z/OS media server issues RACROUTE commands to delete profiles when a volume is deleted from the server. The deletion commands that are issued depend on the current system settings for TAPEVOL and TAPEDSN. If the system settings are changed, the z/OS media server might not delete existing profiles.

Do not change the setting to PROTECTION=AUTOMATIC for a device class that was set to PROTECTION=NO. Volumes without profiles might exist and error messages are generated when such volumes are deleted. If a different value for PROTECTION is required, define a new device class.

Profile creation and deletion occur based on the protection setting when the volume is first used and when it is deleted. The server does not attempt to create profiles for volumes that it has already used. If protection is set to AUTOMATIC, the server attempts to delete profiles when volumes are deleted.

See the documentation for the RACF program for details about the TAPEVOL and TAPEDSN settings and the profiles that are created when these settings are active.

UNIT

Specifies an esoteric unit name to specify a group of tape devices that support ECARTRIDGE tapes. Use the unit name that represents the subset of drives in the library that are attached to the z/OS system. This parameter is optional. The default value is 9840. The unit name can be up to 8 characters.