Reduce memory consumption when consolidating systems

[schuiex]

We are in the process of consolidating all our DEV and QAS systems to one physical system (HP Super dome).

We are consolidate more then 20 SAP instances (Java and ABAP) to on physical system.

The question now is, how to setup the memory requirements (all instance are 64bit and Unicode), during the installation of those instances we defined 4GB for a ABAP instances and 2 GB for a Java instance (Abap+Java 6GB).

In our situation we need around 90GB of main memory.

Does any one have a suggestion how to reduce this amount of memory.

Because this are all DEV and QAS systems and not all the systems are used at the same time. Is it possible to swapout allocated memory for instances which are not used.

Kind Regards,

Evert Schuiteman

[guy_rodesch]

Hi,

We are planning to consolidate the servers too. But we will use a cluster with two physical servers to distribute the resources more adequately by switching the instances between the 2 nodes.

We use Solaris. There is a "resource manager" which permits to limit the utilization of memory and cpu per user. Normally it should also exist a similar concept for HP.

Best regards,

Guy.

[Former Member]

Hi Evert

Because this are all DEV and QAS systems and not all the systems are used at the same time. Is it possible to swapout allocated memory for instances which are not used.

This is possible theoretically, but even if no user is connected and no application job is running, there is still activity on a system, so the only way to free ressources is to stop a system when it is not needed. As memory is cheap, you should rather buy more, than running low on it. If the server starts paging, the sap systems will practically freeze.

You should not forget about the database memory, you will need at least another 2gb for every database.

In my opinion, you should not consider running 20 instances on one server (hard partition on superdomes). We still have several hard partitions on our superdomes running up to 4 sap instances / databases per partition. I strongly suggest to have a "rolling" consolidation, speaking you add systems one after another. This gives you the possibilty to react if any component becomes a bottleneck.

Regards

Michael