XIM uses cross-system coupling facility (XCF) services to locate and connect to other instances of itself within a sysplex. To permit the distribution of utility processes across multiple operating system images, XCF must be executing in a multisystem environment. For more information, see the IBM documentation for the target operating system.
Your site has a defined limit for the number of XCF groups that can be active on a system. You must ensure that using an additional XCF group for XIM does not exceed your defined limit.
To determine whether you can add another XCF group to a system, enter the following console command:
DISPLAY XCF,COUPLE
In the resulting display, review the MAXGROUP(PEAK) and the MAXMEMBER(PEAK) fields for the primary sysplex couple data set. Use the following rules to determine whether you need to increase the XCF group and member limits:
If the value for PEAK in the MAXGROUP(PEAK) field is at least one number less than the value for MAXGROUP, such as 20(19), another XCF group can be added and you can start XIM. If the value for PEAK matches the value for MAXGROUP, you must increase the XCF group limit for the system.
If the value for PEAK in the MAXMEMBER(PEAK) field is at least one number less than the value for MAXMEMBER, such as 20(19), another XCF member can be added and you can start XIM. If the value for PEAK matches the value for MAXMEMBER, you must increase the XCF member limit for the system.
The performance of XIM and other products can be adversely affected by limited buffer availability within XCF. You must ensure that sufficient XCF buffer space is specified for proper XIM execution. For more information, see the IBM documentation.
Important
These values are displayed only when a sysplex couple data set has been defined. When a sysplex couple data set has not been defined, the default values for XCF are used. For more information, see the DEFINEDS statement in the IBM documentation.