Within the dsm.opt file you can tune the following performance-related parameters: TCPWINDOWSIZE TCPBUFFSIZE TXNBYTELIMIT You could also consider using the LAN-free backup to back up your data, as this will send data over the SAN, rather than the LAN. Also, consider how the following issues affect performance: Backups to local shadow volumes do not send data to the Tivoli Storage Manager server. Only metadata is sent to the Tivoli Storage Manager server. During a VSS backup, integrated Exchange integrity checking reads every page in the files to be backed up. This increases the backup time. You can disable the integrity check in some circumstances; however, we do not recommend this. The time required to perform a snapshot ranges from seconds to minutes, depending on the type of VSS provider used. Establish a baseline time for VSS snapshots outside of Tivoli Storage Manager (for example, by using vshadow as described in 3.2.15, "Using vssadmin and vshadow commands" on page 86). 5.6 Managing snapshot-based backups Snapshot-based backups (that is, VSS local backups) are managed by the VSSPOLICY settings. These VSS policy settings are the management classes configured in your Tivoli Storage Manager server. All Local snapshot backups are managed by the Tivoli Storage Manager server version options. These versions will determine how long your data will reside