Tuning AIX systems for Tivoli Storage Manager server performance

There are a number of actions that can improve performance for a Tivoli® Storage Manager server that is running in an AIX® environment.

• Use the rbrw mount option to release memory from the file system cache. For more information about the release-behind sequential read and write (rbrw) option, see the AIX documentation at http://www.ibm.com/support/knowledgecenter/ssw_aix.

  AIX systems can cache much file system data, which can take away memory that is needed for Tivoli Storage Manager server and DB2® processes. To avoid paging with the AIX server, use the rbrw mount option for the JFS2 file system. Less memory is used for the file system cache and more is available for Tivoli Storage Manager.

  Concurrent I/O (CIO) options are not necessary to access or mount database or log file systems. Tivoli Storage Manager completes mounts automatically. Also, CIO disables the read-ahead feature of JFS2 file systems, decreasing the read performance of the database during backup. Do not use the file system mount options, CIO and Direct I/O (DIO), for file systems that contain the Tivoli Storage Manager database, logs, or storage pool volumes. These options can cause performance degradation of many server operations. Tivoli Storage Manager and DB2 can still use DIO where it is beneficial to do so, but Tivoli Storage Manager does not require the mount options to selectively take advantage of these techniques.

• Use the Portable Operating System Interface (POSIX) time zone specification for best system performance.

  If the server is installed on an AIX Version 6.1 operating system, you must use the Portable Operating System Interface (POSIX) time zone specification. The alternative time zone specification, which is based on the Olson database, severely degrades system performance. For information about setting time zone specifications, see the documentation for the AIX operating system. If the server is installed on AIX Version 7.1, this issue does not occur.

• Tivoli Storage Manager supports sharing Fibre Channel ports through NPIV in a pSeries LPAR. While you can share these ports, be sure that the port has adequate bandwidth for all LPARs that use that port. Sharing resources with other logical partitions can affect the performance of the Tivoli Storage Manager server. When there are other logical partitions on the system, you can dedicate resources to the Tivoli Storage Manager server partition.
• Tivoli Storage Manager can use 10-gigabit Ethernet ports that are shared through the VIO server. However, when you use a shared VIO port, it does not always provide full 10-gigabit throughput. If full 10-gigabit Ethernet bandwidth is needed, you can use the logical Host Ethernet Adapter (LHEA) method of sharing.