Recommended service upgrade (RSU)

Recommended Service Upgrade (RSU) is a preventive service philosophy that applies to z/OS®. RSU is intended to reduce the volume of PTFs customers must apply for preventive maintenance and to reduce the chance of encountering a PTF in error (PE), resulting in a more stable system.

IBM® recommends that customers APPLY all RSU PTFs as preventive maintenance on their z/OS systems. However, customers must make the final decision as to what maintenance they will install.

The recommended service for the following products is tested in the Consolidated Service Test (CST) cycle:

z/OS and OS/390®
CICS® Transaction Server for OS/390
DB2® UDB for OS/390
IMS™
MQSeries® for OS/390

Recommended Service Upgrades, with an SMP/E SOURCEID of RSUyymm, are available:

Quarterly, with all PTFs that completed Consolidated Service Test (CST) testing during the prior quarter, including severity 1 through severity 4 APARs.
Monthly, with high impact or pervasive (HIPER) PTFs, PTF-in-error (PE) PTFs, and other recommended PTFs (recommended because of new function, serviceability, installability, security, or integrity) that have been CST tested.

For information about the latest recommended level of service, see the CST and RSU website at http://www.ibm.com/servers/eserver/zseries/zos/servicetst/.

Note: Although all CST-tested PTFs become RSU PTFs, not all RSU PTFs are tested in CST. Only the following systems or applications are included in the CST testing: z/OS, OS/390, CICS, DB2, IMS, and MQSeries.

RSU is provided for z/OS through ESO, CBPDO, and ServerPac.