Solved

AIX NUMA

Posted on 2014-01-22
6
1,252 Views
Last Modified: 2014-01-22
so NUMA..
we have a p780 that host our lpar for one of our oracle prod DB..

this command is showing

lssrad -va                  
REF1   SRAD        MEM      CPU
0
          0   141814.44      0-47 52-55 60-63 68-71 76-79 84-87 92-95
          1   54702.00      48-51 56-59 64-67 72-75 80-83 88-91 96-99

so that menas we have only 2 NUMA domains?

do we need to pursuit any tuning? how can we decide? and what to check?
0
Comment
Question by:it-rex
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3
6 Comments
 
LVL 68

Expert Comment

by:woolmilkporc
ID: 39801420
You have two SRADS (Scheduler Resource Affinity Domains) because you have two hardware sockets (MCM modules) in your machine.

You can only increase the number of SRADs by buying/installing more sockets/MCMs.
0
 
LVL 11

Author Comment

by:it-rex
ID: 39801435
do we need to pursuit any tuning? how can we decide? and what to check?
0
 
LVL 68

Expert Comment

by:woolmilkporc
ID: 39801514
The fewer SRADs in a virtual machine the better.
Lpars should be spread in the minimum number of Chips / Nodes to
reduce the number of Remote & Distant Memory.

Optimizing LPAR placement is quite a complicated task.

Here is a developerworks blog on that topic:
https://www.ibm.com/developerworks/community/blogs/aixpert/entry/local_near_far_power7_affinity_nine_conclusions17?lang=en

During LPAR creation on the HMC you can associate an LPAR with an affinity group.
Put critical LPARs in an affinity group of their own, a single LPAR per group.
0
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 11

Author Comment

by:it-rex
ID: 39801571
so the differnce in memory assigened to each domain

     0   141814.44     0-47 52-55 60-63 68-71 76-79 84-87 92-95
          1   54702.00      48-51 56-59 64-67 72-75 80-83 88-91 96-99

is it something to worry about?
0
 
LVL 68

Accepted Solution

by:
woolmilkporc earned 500 total points
ID: 39801621
I don't know how much memory you have in your machine per socket/MCM
.
If the LPAR demands more memory than can be provided by one physical socket then there is no way around splitting memory across SRADs.

Memory in one SRAD needed by a thread running on a core in the other SRAD is considered "near" or "far"  memory as opposed to "local" memory.
In your case both SRADs are in the same building block (because they're both in REF1 (Node) 0) so we're talking about "near" memory - access to near memory has to go through the "Power Chip to Power Chip Intra-node communication path" which shouldn't cost much time.

The fundamental proposition is still: The fewer SRADs the better. See my hints on LPAR placement optimization.
0
 
LVL 11

Author Comment

by:it-rex
ID: 39801639
thanks
0

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I have been running these systems for a few years now and I am just very happy with them.   I just wanted to share the manual that I have created for upgrades and other things.  Oooh yes! FreeBSD makes me happy (as a server), no maintenance and I al…
Every server (virtual or physical) needs a console: and the console can be provided through hardware directly connected, software for remote connections, local connections, through a KVM, etc. This document explains the different types of consol…
Learn how to navigate the file tree with the shell. Use pwd to print the current working directory: Use ls to list a directory's contents: Use cd to change to a new directory: Use wildcards instead of typing out long directory names: Use ../ to move…
In a previous video, we went over how to export a DynamoDB table into Amazon S3.  In this video, we show how to load the export from S3 into a DynamoDB table.

733 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question