UPDATE DEVCLASS (Update a REMOVABLEFILE device class)
Use the REMOVABLEFILE device class for removable media devices that are attached as local, removable file systems.
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 updated.
- LIBRary
- Specifies the name of the defined library object that contains the removable media drives used by this device class. This parameter is optional. For information about defining a library object, see the DEFINE LIBRARY command.
- MAXCAPacity
- Specifies the maximum size of any volumes that are defined to a storage pool categorized by this
device class. This parameter is optional.
Because the server opens only
one file per physical removable medium, specify a capacity that enables one file to make full use of
your media capacity.You must specify this value as an integer followed by K (kilobytes), M (megabytes), G (gigabytes), or T (terabytes).
For example, MAXCAPACITY=5M specifies that the maximum capacity for a volume in this device class is 5 MB. The smallest value that is allowed is 1 MB (that is, MAXCAPACITY=1M).
- MOUNTRetention
- Specifies the number of minutes that an idle sequential access
volume is retained before it is dismounted. This parameter is optional.
You can specify a number 0 - 9999.
This parameter can improve response time for sequential access media mounts by leaving previously mounted volumes online.
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. 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. 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.