SERVERDEDUPTXNLIMIT

When you use duplicate-identification processes (the IDENTIFY DUPLICATES command) for large objects, intensive database activity can result from long-running transactions that are required to update the database. High levels of database activity can produce following symptoms:

• Reduced throughput for client backup and archive operations
• Resource contention resulting from concurrent server operations
• Excessive recovery log activity

The extent to which these symptoms occur depends on the number and size of objects being processed, the intensity and type of concurrent operations taking place on the Tivoli® Storage Manager server, and the Tivoli Storage Manager server configuration.

With the SERVERDEDUPTXNLIMIT server option, you can specify a maximum size, in gigabytes, for objects that can be deduplicated on the server. If an object or set of objects in a single transaction exceeds the limit specified by SERVERDEDUPTXNLIMIT, the objects are not deduplicated by the server. You can specify a value 32 - 2048 GB. The default value is 300 GB.

Increasing the value of this option causes the Tivoli Storage Manager server to search for objects previously deferred whose size falls below the new transaction limit.

The appropriate value for this option depends on the Tivoli Storage Manager server configuration and concurrent server activity. You can specify a high value for this option if you minimize resource contention. To minimize resource contention, perform operations, such as backup, archive, duplicate identification, and reclamation, at different times.

To update this server option without stopping and restarting the server, use the SETOPT command.

                        .-300-------.   
>>-SERVERDEDUPTXNlimit--+-gigabytes-+--------------------------><

Parameters

gigabytes

Specifies the maximum size, in gigabytes, of objects that can be duplicated on the server. You can specify a value 32 - 2048. The default value is 300.

serverdeduptxnlimit 120