IBM Tivoli Storage Manager for UNIX and Linux Backup-Archive ...

Retryperiod2. The Tivoli Storage Manager server can set the maximum number of mountpoints a node can use on the server using the MAXNUMMP parameter. If theresourceutilization option value exceeds the value of the MAXNUMMP on theserver for a node, the backup can fail with an Unknown System Error message.3. You can get a multi-session restore from your single restore command, andfrom a single volume on the server, if that volume is device class FILE.For example, if the data you want to restore is on 5 different tape volumes, themaximum number of mount points is 5 for your node, and resourceutilization isset to 3, then 3 sessions will be used for the restore. If you increase theresourceutilization setting to 5, then 5 sessions will be used for the restore. Thereisa1to1relationship to the number of restore sessions allowed for theresourceutilization setting. Multiple restore sessions are only allowed for no queryrestore operations.Multiple client session considerationsThis topic lists some items to consider when working with multiple client sessions.The following factors can affect the throughput of multiple sessions:v The server’s ability to handle multiple client sessions. Is there sufficient memory,multiple storage volumes, and CPU cycles to increase backup throughput?v The client’s ability to drive multiple sessions (sufficient CPU, memory, etc.).v The configuration of the client storage subsystem. File systems that are stripedacross multiple disks, using either software striping or RAID-5 can better handlean increase in random read requests than a single drive file system. Additionally,a single drive file system might not see performance improvement if it attemptsto handle many random concurrent read requests.v Sufficient bandwidth in the network to support the increased traffic.Potentially undesirable aspects of running multiple sessions include:v The client could produce multiple accounting records.v The server might not start enough concurrent sessions. To avoid this, the servermaxsessions parameter must be reviewed and possibly changed.v A query node command might not summarize client activity.The retryperiod option specifies the number of minutes the client scheduler waitsbetween attempts to process a scheduled command that fails, or betweenunsuccessful attempts to report results to the server. Use this option only when thescheduler is running.You must be an authorized user to use the retryperiod option.Your administrator can also set this option. If your administrator specifies a valuefor this option, that value overrides the value in your client system options fileafter your client node successfully contacts the server.Supported ClientsThis option is valid for all clients. The Tivoli Storage Manager client API does notsupport this option.Chapter 10. Using processing options 381