Enabling secondary host promotion from the SETSYS command

For either a base or parallel sysplex, DFSMShsm, using XCF, can enable secondary hosts to take over any unique functions that are performed by the failed primary host. There can be three types of failures:

DFSMShsm placed in emergency mode
DFSMShsm address space failures
Entire z/OS image failures

Likewise, another host within an HSMplex can assume the responsibilities of any host (either the primary or secondary host) that is performing secondary space management, if the host performing SSM fails.

Rule: To enable secondary host promotion, you must configure XCF on the active DFSMShsm system. DFSMShsm must be running in multisystem mode.

To enable secondary host promotion, specify the SETSYS PROMOTE command with either or both of the following parameters:

PRIMARYHOST(YES|NO)
SSM(YES|NO)

where

PRIMARYHOST(YES): You want this host to take over primary host responsibilities for a failed host.
PRIMARYHOST(NO): You do not want this host to take over primary host responsibilities for a failed host.
SSM(YES): You want this host to take over the SSM responsibilities for a failed host.
SSM(NO): You do not want this host to take over the SSM responsibilities for a failed host.

Note:

NO is the default for both SETSYS PROMOTE parameters (PRIMARYHOST and SSM).
Only those DFSMShsm hosts running on DFSMS/MVS Version 1 Release 5 and above are eligible to use secondary host promotion functions.
This parameter is ignored when the system is running in LOCAL mode. If the system is running in MONOPLEX mode, the secondary host promotion function is active, but is unable to perform actions because cross-host connections are not enabled.
An SSM host is not eligible to be promoted for another SSM host.
PRIMARYHOST(YES) is ignored if it is issued on the primary host.
The SETSYS command does not trigger promotion. That is, a host can only be eligible to be promoted for hosts that fail after the SETSYS command has been issued.
Do not make a host eligible for promotion if its workload conflicts with responsibilities of the original host or if it is active on a significantly slower processor.