These items warrant consideration since they have potential for a negative impact to performance.
- Performance APARs
- Large VM Systems
There are a number of z/VM 5.3 APARs that correct problems with performance or performance management data. Review these to see if any apply to your system environment.
This was first listed as a consideration for z/VM 5.2 and is repeated here. Because of the CP storage management improvements in z/VM 5.2 and z/VM 5.3, it becomes practical to configure VM systems that use large amounts of real storage. When that is done, however, we recommend a gradual, staged approach with careful monitoring of system performance to guard against the possibility of the system encountering other limiting factors.
With the exception of the potential PGMBK constraint, all of the specific considerations listed for z/VM 5.2 continue to apply.