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The SERVER device type is used for special device classes whose storage volumes are not directly attached to this server. A volume with device type SERVER consists of one or more files archived in the server storage of another server, called a target server. You can define this device class by issuing a DEFINE DEVCLASS command with the DEVTYPE=SERVER parameter. For information about how to use a SERVER device class, see Using Virtual Volumes to Store Data on Another Server.
Other parameters specify how to manage data storage operations for the new device class:
You can update the device class information by issuing the UPDATE DEVCLASS command.
The Tivoli Storage Manager server on which you define a SERVER device class is called a source server. The source server uses the SERVER device class to store data on another Tivoli Storage Manager server, called a target server.
When defining a SERVER device class, specify the name of the target server. The target server must already be defined by using the DEFINE SERVER command. See Using Virtual Volumes to Store Data on Another Server for more information.
Use the mount limit value for SERVER device classes to restrict the number of simultaneous sessions between the source server and the target server. Any attempts to access more sessions than indicated by the mount limit causes the requester to wait. The default mount limit value is 1. The maximum value for this parameter is 256.
When selecting a mount limit, consider your network load balancing and how many Tivoli Storage Manager processes you want to run at the same time.
Tivoli Storage Manager automatically cancels some processes to run other, higher priority processes. If the server is using all available sessions in a device class to complete higher priority processes, lower priority processes must wait until a session becomes available. For example, Tivoli Storage Manager cancels the process for a client backup if a session is needed for a server migration or reclamation process. Tivoli Storage Manager cancels a reclamation process if the session being used is needed for a client restore operation.
If processes are often cancelled by other processes, consider whether you can make more sessions available for Tivoli Storage Manager use. Otherwise, review your scheduling of operations to reduce the contention for network resources.
You can specify a maximum capacity value that restricts the size of objects that are created on the target server to store data for the source server. The default MAXCAPACITY value is 500MB.
You can specify a prefix that the source server will use as the beginning portion of the high-level archive file name on the target server.
You can specify a retry period for communications with the target server. When there is a communications failure, this period determines the amount of time during which the source server continues to attempt to connect to the target server.
You can specify how often the source server tries to connect to the target server when there is a communications failure. During the retry period, the source server tries to connect again as often as indicated by the retry interval.