Hello,
last year I have migrated our Solaris Based SAP Systems to Linux on VMware. At this time I had a look to a good konfiguration of SAP Instances and serverlandscape.
Now I am using:
DB and CI (no Users): 24 CPU, 196 GB RAM - 25 % CPU usage
Dialog Instances: 16 CPU, 128 GB RAM - 16 % CPU usage
4 Instances for users with following configuration: 40 Dialog, 10 Batch, 6 Update, 3 Update2, 2 Spool
1 Instance for Interfaces (mostly with sleeping Jobs): 40 Dialog, 30 Batch, 6 Update, 3 Update2, 2 Spool
The system is running very fine, but I am still searching for optimization and knowledge,
Actually I am thinking of enlarging DB-Server to 30 CPU and moving the dialog instances to this server.
Pro:
better distribution of CPU-ressources
easier administration, espacially directory and OS-User handling
Contra:
risk of conflict in CPU ressources between DB and SAP
Also I would try to reduce the number of SAP instances, because I would like to benefit of shared buffers and avoid buffer synchronisation conflicts. Optimum would be only one instance, but I am not able to create sufficient work processes.
I have read multiple times, that a larger number of small instances are to be prefferred to some large instances.
What are your experiences?
Best Regards
Andreas