Before we look further in to memory affinity we need to recap on the scheduling of processes and process threads of a multi-threaded process to simultaneous multi-threading (SMT) processors like POWER7.  POWER5 and POWER6 had two modes of SMT off (one thread) and on (two threads) - with SMT=on two processes run at the same time (in the same clock cycle) on the CPU-core but using the different logical units inside of the CPU-core (units like the integer maths (there is more than one), floating point maths (there is more than one), compare and... [More]

Tags:  logical core powervm vp aix smt power7 processor power

Update in 2016: Please note this blog is from 2011 during the initial POWER7 days and technology has moved on with faster CPUs and memory in addition there has been software improvements.  I am amazed how many good computer people read this and assume this blog is true to all time! Virtual Ethernet is faster now but there is also a warning here. Here is an analogy. Most vehicles can do 10 MPH (including me on a bike), most cars can do 100 MPH (including my family car) but very few vehicles can do 1000 MPH. That last times ten multiplier is... [More]

Tags:  vios machine misunderstood power6 power7 aix virtual ethernet speed powervm

I need you to help me settle an argument or rather lack of information. I am getting conflicting messages about whether these smaller Power7 machines use Local and Near or Local and Far memory. I documented what I thought was correct in the Part 1 of this series of blog's.   Actually, there is not much difference as these machines have two tiers of memory like "on the chip" or "some where else" so the names are hardly vital but I would like my facts straight. Unfortunately, I don't have examples of these machines with more... [More]

Tags:  730 affinity lssrad 740 srad 710 750 lpar aix power powervm 720 power7 vm

So you know about Power7 Local, Near and Far memory for your actual machine but what is your Virtual Machine (LPAR) actually using? There are three key commands to show you (lssrad, mpstat and topas) and we will look at some example output.   First, we need to define an SRAD or a Scheduler Resource Affinity Domain .  If you have used Resource Sets with AIX WLM or WPAR then you have a good idea what these are like. An SRAD is a group of resources but in our case CPU/cores and the associated memory that is directly attached to it. As an... [More]

Tags:  lssrad topas affinity mpstat srad powervm aix6 power7 resource aix7 domain scheduler

 I am using the VIOS Shared Storage Pools more these days and it reduces my system admin time and I really like the Thin Provisioning feature as I have limited SAN disks. Any way, I dusted off an machine that I did my initial investigation on and decided to rebuilt the cluster (of one VIOS) now that I know what I am doing :-)    The  command : cluster -create -clustername galaxy  -repopvs hdisk2   -spname atlantic -sppvs hdisk3 hdisk4 hdisk5   -hostname diamondvios1 fails with "PV IS IN USE hdisk4".  PV meaning Physical Volume. Yes,... [More]

Tags:  cluster disks clean power7 storage disk power6 pools aix reusing shared vios

 On Power6 the largest machine was the Power 595 with 64 Physical CPUs (cores) across eight CPU books in the machine - each CPU book having 4 Power6 chips and so 8 CPUs (Power6 is a dual CPU chip design). However, with Power7 that has stepped up to 256 CPUs across the same eight CPU books with four chips but with 8 CPUs each so that is 32 CPUs per book.  I might be stating the obvious but memory access to memory directly attached to the Power chip on which your process is running is slightly faster than memory access via a Power chip near by... [More]

Tags:  near 770 far powervm aix power7 local 795 780 power6

 This mysterious AIX CPU Folding area is often misunderstood, so below is what I know from osmosis from talking to various guru level developers over the last 10 years. Shared Processor virtual machines (LPARs for the old fashioned) have a setting called Virtual Processors (or VP for short). This is the number of physical CPUs that the virtual machines can spread out across - in fact, I prefer to call it the "spreading factor" as it is much more obvious what it means.  This can be the upper threshold for the number of CPUs that can be... [More]

Tags:  power7 powervm power6 hypervisor aix folding aix6 aix7 virtual processor

I just noted two great new things to help those running Java on AIX and it seems hard to avoid Java these days!  I was just monitoring a customer machine with 1500 WebSphere Application Servers (WAS) each with 100 to 150 threads so roughly 200,000 threads!!!  More impressing was that just 20 Power7 physical CPUs was supporting this workload.   So here are two things that can help: 1. Java Performance Advisor (JPA) Available for download to anyone on IBM DeveloperWorks website. This is a powerful new tool to help people identify opportunities to... [More]

Tags:  whitepaper tuning best tool power6 on power7 practice aix and java

Here is another question from that larger Power 7 machine customer. They have large Virtual Machines (Logical Partitions) and can't see all the CPUs on the screen. This is made worst by Power 7 machines - not a problem with the processors or machines but there are: So many CPUs on larger machines like Power 770/780 and the mighty Power 795 Then the new Simultaneous Multi-Threading (SMT) now means four threads per physical CPU (core). This means lots of physical CPUs and each has four logical CPUs.  So what happens on the screen - you see a... [More]

Tags:  nmon physical longer cpu power aix powervm term

I am working with a larger Power 7 customer and learning lots about life in the large and professional computer room. Oh Gosh!!! My Power Virtual Machine (Logical Partition) is totally busy. Oh Heck!!! Look at all that System time, we have a serious problem!! Or do we? Take a look at the below nmon stats and make up your own mind before scrolling down.         Actually, we are in offices many miles away from most of the Power 7 computers because the machines are split across three sites.  More than twenty Power 7 Model 795's is enough to... [More]

Tags:  tl06 time aix system power performance nmon tl05

So you have Discovered, given Access and run Inventory on your HMC and it is not finding the Servers and Virtual Servers that the HMC is connected too! What do you do next? Well here are a series of suggestions for you to try (this is not an official diagnostics path but might help you out): How much memory has your HMC got? I get people trying to use old HMCs and the original ones had just 1 GB of memory. This is basically not enough these days - in my humble opinion - unless you have just one machine! But how do you find out what you have?... [More]

Tags:  aix power7 powervm director hmc power6 systems

I just moved our Power 5 based internal to IBM Wiki Webserver to Power 6 p570 which was recently freed up now that we (Advanced Technical Support, EMEA) are mainly working on the Power 7 machines. The Power 6 machine are still very useful for testing beta copies of new software like AIX and the end of year VIOS functions but some features are Power 7 dependent. We are removing the Power 5 machines because we are moving building and to a much smaller computer room and have to move from 15 racks down to 5 racks. We have been a little lazy in... [More]

Tags:  vios 6 storwize asmi power7 upgrade apache power aix webserver

I often get asked: How large to make a pair of Virtual I/O Server (VIOS)? The classic consultant answer is "it depends on what you are doing with Disk & Network I/O" is not very useful to the practical guy that has to size a machine including the VIOS nor the person defining the VIOS partition to install it! Added new guidance at the bottom in RED Observations : The VIOS server unfairly gets a bad press but note: Physical adapters are now in the VIOS, so device driver CPU cycles (normally hidden and roughly half of the OS CPU... [More]

Tags:  vios aix i/o sizing virtual power6 power7 server linux

I have just upgraded my EMEA Power Systems Advanced Technical Support internal Wiki Apache Web-server to the very latest AIX level, which is AIX 6.1 Technology Level 6 Service Pack 5 or AIX6.1TL6sp5 for short! Then I noticed that the nmon at this AIX level has been updated - I worked the code for the internal prototype of this new feature some time ago and it has arrived in the official topas/nmon code at this release - C O O L .   The latest release AIX 7.1 service pack has this new options too. The problem: As the numbers of CPU goes up with... [More]

Tags:  power6 power7 tl06 sp5 6.1 aix monitoring topas nmon physical cpu

Active Memory Expansion (AME) can second in my Top Ten Technologies to be business as usual in the next few years from hundreds of votes world wide. It is available on Power7 machines with AIX 6.1 TL4 SP2 onwards and AIX 7, of course. This allows memory to look at lot bigger than it actually is - to allow more LPARs to be running on a machine or giving headroom for boosts performance. The usefulness of AME is all down to the Expansions Factor (EF) - which is based on the compression ratio achieved for memory pages. If the EF very low then you... [More]

Tags:  memory factor expansion ame ram aix power7

For Systems Director 6.2 supports Firefox 3.6, 3.5 and 3.0 - you have to be nuts to not be using 3.6 IMHO! Internet Explorer 7 or 8. See http://publib.boulder.ibm.com/infocenter/director/v6r2x/index.jsp?topic=/com.ibm.director.plan.helps.doc/fqm0_r_supported_web_browsers.html Unofficially, I find Google Chrome 12 works fine too. For Hardware Management Console (HMC) (I am assuming a recent HMC V7R7.3 level here) it supports (from the Power7 manuals) Internet Explorer 7 but says IE 8 is not supported - just tried this and the left hand menu got... [More]

Tags:  ie console management director explorer chrome systems internet hardware firefox hmc

We have had the Global Services offering "Performance Management for AIX" server for years (even decades) - it gets shorten to "PM for AIX" or "PM for Power Systems" which sounds like a "Prime Minister for the Electricity Board" to English people!  Anyway, briefly this offers: PM collects local AIX stats and configuration details, then sends the information to IBM over a secure Internet link to be analysed. The results includes performance graphs, performance trends, config reports and warnings about... [More]

Tags:  management recording performance tl06 topas aix 6.1 smitty pm

   While I was installing a re-purposed POWER6 machine over the weekend, got round to installing my Dual Virtual I/O Servers, from DVD and then upgrading from there and I noticed a new service pack 2 for the latest VIOS version. It must have sneaked out without me noticing and there is a Interim fix too.  The VIOS 2.2.0.12-FP24 SP2 Readme highlights lots of fixes including some for the Shared Storage Pool feature. A feature that I have been using and talking about (see this blog for more information).     This got me thinking!  I talk to lots... [More]

Tags:  power7 server vios recommended aix levels i/o virtual power powervm

With Systems Director and VMControl Standard Edition (this was called Image Manager), you can Capture an AIX Virtual Server to an appliance in the VMControl Repository. Then later Deploy the appliance to a new Virtual Server on a different Power machine. What this means in proper technical "AIX speak" is Systems Director can: Create a mksysb to a NIM server and also save the LPAR settings (numbers of CPU, RAM, network and disks). Later you can perform a NIM client install from the mksysb and it automatically uses the same LPAR... [More]

Tags:  director vmcontrol appliance modify systems aix