Memory Management on Linux machine with 32 GB RAM

[Former Member]

Hi Pros.

I have two questions regarding memory management with Linux (ERP 2005).

1. For our productive System we want to use 4 new servers (x86_64) with SLES 10 SP 2. Each of them has 32 GB RAM (and 64 GB SWAP Space).

We want to install one Dialog Instance per Server. Central Instance is running on AIX / P5.

Can you give me some tipps how to customize the memory management?

em/initial_size_MB

ztta/roll_extension (_dia / _nondia)

abap/heap_area_total

abap/heap_area_dia

abap/heap_area_nondia

...

I want to use STD-Implementation of memory management (es/implementation = STD)

2 For our development systems we have two servers (also SLES 10 SP2, 32 GB RAM, ...)

Each of them should run the following dialog instances

- one DI Development System

- one DI Testsystem

- one DI for BI Development

- one DI for Development Portal

- one DI for Test Portal

The question is the same as above. Can you give me some tipps for the memory management?

Thanks a lot in advance & best regards,

Martin

[Former Member]

Hello, Do you have any documentation on how you installed the System on AIX W/ Linux Appservers?

Thanks,

[markus_doehr2]

Linux on Power or Linux on x64?

Markus

[martin_juen2]

Our Central Instance is running on Power PC (AIX 5.3). Our new Dialog instances are running on X86_64 (HP Blade Server / SLES 10).

best regards,

Martin

[martin_juen2]

What do you mean with "special" documentation?

Our Central Instance was installed in the mid 90s - i have no documentation of these installation process. The installation of DIs is written down - in german. i don't know if these info will help you (because its a standard process)...

Martin

[markus_doehr2]

Our Central Instance is running on Power PC (AIX 5.3). Our new Dialog instances are running on X86_64 (HP Blade Server / SLES 10).

You can check the "normal" installation guides at

http://service.sap.com/instguides

--> SAP Business Suite Applications

--> SAP ERP

--> SAP ERP 6.0

--> Installation

---> SAP ERP 6.0 SR3 - Installation Documentation

and there section "3.2.5 Requirements for a Dialog Instance".

Be aware of the following fact:

- If it´s a non Unicode system there will be differences in sorting for the users (due to different locale)

- If you´re accessing binary data on filesystem you may run into problems (AIX is BigEndian, Linux x64 is LittleEndian)

- you will either need a separate directory on the CI or keep your kernels and patchlevels manually in sync with the CI

Markus

[martin_juen2]

thanks for your infos.

[markus_doehr2]

> Can you give me some tipps how to customize the memory management?

> em/initial_size_MB

> ztta/roll_extension (_dia / _nondia)

> abap/heap_area_total

> abap/heap_area_dia

> abap/heap_area_nondia

This depends on number of users, applications used... To get a start I would

If only those instances are running I would give spontaneously

em/initial_size_MB 25000

ztta_roll... 2,000,000,000

abap_heap_area_total, dia, nondia 2,000,000,000

you may need to increase those if the applications demand it.

> I want to use STD-Implementation of memory management (es/implementation = STD)

good choice!

> 2 For our development systems we have two servers (also SLES 10 SP2, 32 GB RAM, ...)

> Each of them should run the following dialog instances

> - one DI Development System

> - one DI Testsystem

> - one DI for BI Development

> - one DI for Development Portal

> - one DI for Test Portal

you plan to run them all on the bare metal or do you plan to use Xen?

Markus

[martin_juen2]

P-System

Only one Dialog instance per Server (we run 80 clients and modules like banking on this system)

D-System

At the moment we want to use the machines bare metal.

Thanks,

Martin

[markus_doehr2]

P-System

Only one Dialog instance per Server (we run 80 clients and modules like banking on this system)

Don´t know how your application structure looks like and if 2 GB heap_area is enough but it´s a good start

Size your buffer amply (abap/buffersize et al)

D-System

At the moment we want to use the machines bare metal.

ِPossible - but administration of a multiple instance system can be tricky. XEN doens´t need much power (< 15 %) and it enables you to have isolated instances that can be nicely patched each of itself. How much memory those single instances need (either on Xen or not) is again a matter of number of users and how much you really "need". I´d go for 8 - 10 GB per instance, maybe less if you plan to run the databases on the same system.

Markus