DEFINE DEVCLASS (Define a NAS device class)
Use the NAS device class when you are using NDMP (Network Data Management Protocol) operations to back up network-attached storage (NAS) file servers. The device class is for drives that are supported by the NAS file server for backups.
The NAS device class does not support EXTERNAL libraries.
The NAS device class does not support EXTERNAL or Remote Storage Manager libraries.
Privilege class
To issue this command, you must have system privilege or unrestricted storage privilege.
Syntax
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.
- DEVType=NAS (Required)
- Specifies that the network-attached storage (NAS) device type is assigned to the device class. The NAS device type is for drives that are attached to and used by a NAS file server for backup of NAS file systems.
- LIBRary (Required)
- Specifies the name of the defined library object that contains the SCSI tape drives used by this device class. For information about defining a library object, see the DEFINE LIBRARY command.
- MOUNTRetention=0 (Required)
- Specifies the number of minutes that an idle sequential access volume is retained before it is dismounted. Zero (0) is the only supported value for device classes with DEVType=NAS.
- 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.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 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.
- 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.
- ESTCAPacity (Required)
- Specifies the estimated capacity for the volumes that are assigned
to this device class.
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.
- 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.
- 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:
Example: Define a NAS device class
define devclass nastape devtype=nas library=naslib
mountretention=0 mountlimit=drives
prefix=smvol estcapacity=200G