Use the GENERICTAPE device class for tape drives that are supported by operating system device drivers.
When you use this device type, the server does not recognize either the type of device or the cartridge recording format. Because the server does not recognize the type of device, if an I/O error occurs, error information is less detailed compared to error information for a specific device type (for example, 8MM). When you define devices to the server, do not mix various types of devices within the same device type.
Privilege class
To issue this command, you must have system privilege or unrestricted storage privilege.
Syntax
>>-DEFine DEVclass--device_class_name---------------------------> >--LIBRary--=--library_name--DEVType--=--GENERICtape------------> .-MOUNTRetention--=--60------. >--+----------------------+--+----------------------------+-----> '-ESTCAPacity--=--size-' '-MOUNTRetention--=--minutes-' .-MOUNTWait--=--60------. .-MOUNTLimit--=--DRIVES-----. >--+-----------------------+--+---------------------------+---->< '-MOUNTWait--=--minutes-' '-MOUNTLimit--=--+-DRIVES-+-' +-number-+ '-0------'
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 the defined library object that contains the tape drives that can be used by this device class.
For information about defining a library object, see the DEFINE LIBRARY command.
- DEVType=GENERICtape (Required)
- Specifies that the GENERICTAPE device type is assigned to the
device class. GENERICTAPE indicates that the volumes for this device
class are used in tape drives that are supported by the operating
system's tape device driver.
The server recognizes that the media can be removed and that more media can be inserted, subject to limits set with the MOUNTLIMIT parameter for the device class and the MAXSCRATCH parameter for the storage pool.
Volumes in a device class with device type GENERICTAPE are sequential access volumes.
- ESTCAPacity
- Specifies the estimated capacity for
the volumes that are assigned to this device class. This parameter
is optional.
You can specify this parameter if the default estimated capacity for the device class is inaccurate due to compression of data.
Specify a capacity appropriate to the particular tape drive that is being used.
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.
- MOUNTRetention
- Specifies the number of minutes that an idle sequential access
volume is retained before it is dismounted. This parameter is optional.
The default value is 60 minutes. You can specify a number 0 - 9999.
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.
Note: For environments in which devices are shared across storage applications, the MOUNTRETENTION setting must be carefully considered. This parameter determines how long an idle volume remains in a drive. Some media managers do not dismount an allocated drive to satisfy pending requests. You might need to tune this parameter to satisfy competing mount requests while maintaining optimal system performance. Typically, problems arise more frequently when the MOUNTRETENTION parameter is set to a value that is too small, for example, zero. - MOUNTWait
- Specifies the maximum number of minutes the server waits for an operator to respond to a request to either mount a volume in a drive in a manual library or check in a volume to be mounted in an automated library. This parameter is optional. If the mount request is not satisfied within the specified amount of time, the mount request is canceled. The default value is 60 minutes. You can specify a number 0 - 9999.
- 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 DRIVES. You can specify a number 0 - 4096.
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.
The following are possible 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.
- Note: For EXTERNAL library types, do not specify DRIVES for the MOUNTLIMIT value. Specify the number of drives for the library as the MOUNTLIMIT 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.
- 0 (zero)
- Specifies that no new transactions can gain access to the storage pool. Any current transactions continue and complete, but new transactions are terminated.