IBM Magstar 3494 manual Host-Initiated Operations, Mount Operations

Operations

The 3494 performs host-initiated and stand-alone operations.

Host-Initiated Operations

The following are host-initiated operations:

vMount operations

vDemount operations

vEject operations

vAudit operations

vImport operations

vExport operations

Mount Operations

Host-initiated mount operations result in either a physical or logical mount being performed by the library. Whether the host-initiated mount is physical or logical is determined by the drive address to which the mount is issued. When issued to a drive address within a Virtual Tape Server, the library performs a logical mount operation. For all other drive addresses, a physical mount operation is performed.

The library manager directs the cartridge accessor to move a physical volume from its current location to the speci®ed drive. The following are types of mount operations:

Mount speci®c

The speci®c volser to be mounted is speci®ed in the mount request.

Mount from category

The volser to be mounted is picked from the speci®ed category in the mount request.

Physical mount operations result in a volume being placed in a drive and loaded by the drive. Physical mounts are performed by the cartridge accessor.

Mounts for logical volumes are performed by the Virtual Tape Server. They may or may not require a physical mount.

Logical mount operations result in a virtual volume being made available to the host through a virtual tape drive. Following are the types of logical mount operations:

Fast-Ready Mount

The host requested a category mount and the category was designated as a ªFast-Readyº category. This type of mount selects a volser from the speci®ed category and logically mounts it on the virtual tape drive. An odd/even volser selection algorithm is used to maximize VTS performance. No recall of the data from the prior use of the volser from physical tape is performed.

Cache Mount

The host requested a speci®c volser and the virtual volume for that volser is resident in the tape volume cache. No recall of data from a physical tape is performed.

Chapter 3. Operational Characteristics 55