RAM Calculations

[Former Member]

Hi Team,

This query to get some of your expertise on how do we go on deciding/dividing RAM in Windows OS, MS SQL Server platform.

For example:

1. systems - 3 (1-dedicated DB node, 1-CI node along with DI, 1-dedicated DI)

With each system we have 100 GB and we are planning for ABAP + JAVA.

And I understand the memory configuration would certainly have dependence on # work process on ABAP stack and # Java Server nodes on Java stack. If not specific to this query along with the informed info but rather you can give me some brief example to make me understand would highly appreciated.

-sekhar

[Former Member]

Hello,

You only mention dedicated database nodes and dedicated SAP instance nodes, so the traditional 60/40 rule does not apply in your case (unless you are setting up a cluster, in which case you must take into account that the database and the SAP CI/DI may find themselves running on the same node).

For the database follow the recommendations of note 879941 (for SQL Server 2005). The basic rule is that you give as much RAM as possible to the database. Always use fixed allocation, i.e. minimum = maximum.

For the Java stack, use the formula from note 723909, which amounts to ~2.5 GB per server node.

For the ABAP stack on Windows, you should use Zero Administration Memory Management, which implies that you only set the profile parameter PHYS_MEMSIZE and let the SAP kernel derive proper memory sizing. Set PHYS_MEMSIZE to the RAM of the server minus the allocation you have estimated for the Java stack.

These are initial guidelines and you'll need to do some monitoring and fine-tuning but, to be honest, I don't expect that with 100 GB per server you will have too many problems.

Hope this helps,

Mark

[Former Member]

Hi,

As per my little knowledge, have read some where in RZ11 of profile parameters related to memory that in a system with both SAP and DB installed, 60% of RAM will be used for SAP and 40 % will be use by database.

Thanks & Regards,

Sharath