IBM Z System Recovery Boost
In a System Automation environment, typical recovery situations are IPL and system shutdown. When a recovery situation is ongoing, normal workload processing stops. The objective of System Recovery Boost is to reduce the time to shut down, restart the system, process the backlog that accumulated during a system outage, and accelerate some sysplex recovery situations, by providing additional process capacity for the boosted image.
System Recovery Boost was introduced with IBM z15. On IBM Z subcapacity models, z/OS and other operating systems with this feature can temporarily run their shared general-purpose processors at full speed during boost periods. On IBM Z with zIIPs installed, z/OS images with shared zIIPs configured can run workloads that are designated for general-purpose processors, while in boost mode. Specific IBM Z temporary capacity records are offered to gain additional boost capabilities on demand.
Entering and leaving boost mode is managed on operating system level and includes activation procedures for the user. IBM terms and conditions regulate what boost periods are, their length, and usage frequency. Besides IPL and shutdown, IBM has grouped entitled boost mode use cases in recovery classes. For more information, see the white paper System Recovery Boost for the IBM z15.
System Recovery Boost Support in System Automation
Recovery Situations
At IPL time, a system can automatically participate in the boost unless the BOOST system parameter in IEASYSxx is set to NONE.
At shutdown time, System Automation can automatically activate System Recovery Boost upon shutdown of a system. For more information, see Automatic Activation of System Recovery Boost Upon System Shutdown in IBM Z® System Automation Customizing and Programming.
Boost Status Monitoring
The target systems with an active SNMP connection to a ProcOps focal point are monitored if their LPARs are entering or leaving the boost mode. This monitoring is part of the standard connection polling. You can configure the poll frequency for a connection in the Processor Information policy of your policy database.
For target systems with the SYSCONS activated, the automation of z/OS messages indicating a boost mode change also update this status in ProcOps. To query the boost mode, you can use the ISQXDST Target Status Summary and Target System Summary panels or use the ISQVARS GET command with the target attention (TATTN) keyword. If the target system's LPAR is in boost mode, you can use the ISQCCMD GETIBOOST tgtname OPT(STATUS) to retrieve mode details.
The boost mode background monitoring by System Automation is useful because the IBM Z firmware itself does not emit an event if an image's boost mode change.
System Programmer Assistance
You can use the ISQCCMD GETIBOOST OPT(EVALUATE) command to collect IBM Z hardware information to evaluate if the CPC and LPARs are 'BOOST' capable and what is their ready state. The returned information includes the CPC's full or subcapacity indicator, the number of the physical installed zIIPs, the number of the shared zIIPs on LPAR level and capacity records IDs with zIIP capacity. Since ProcOps has enterprise scope, you can run automated and scheduled queries without a need to log in to any Hardware Management Console (HMC).