AIXpert Blog is about the AIX operating system from IBM running on POWER based machines called Power Systems and software related to it like IBM Systems Director, PowerVM for virtualisation and PowerSC for security plus performance monitoring and nmon
As we all know, the advanced PowerVM virtualisation functions of POWER7 based machines are implemented in the hardware (the POWER7 processor itself and the System Firmware, which includes PowerVM Hypervisor) for increased security, high performance and reliability. After more than a year of POWER7 field experience and fixes to increase RAS, further development of still more virtualisation functions and improved algorithms for higher performance - it is very important for all of us to install the newer levels of System firmware to avoid already... [More]
I have been running the nmon ( n igel's mon itor) for AIX project for 15 years now but I am still learning. I initially wrote it to help me run AIX 3.2 then AIX 4 benchmarks on RS/6000 machines as running the older "down the screen" and "line by line" tools like vmstat and iostat was driving me mad (literally making my eye hurt) and so using screen curses enabled the number to stop moving on the screen. nmon's second most important feature was to make graphing the results simpler as a graph includes the time dimension, it... [More]
I spent two days with a "well known brand" UK retailer trying out Versioned Workload Partitions (vWPAR). Actually, it was with an IBM Business Partner that runs the machines for them- two knowledgeable and fun guys to work with - we were asked by the European manager in the next room to keep the noise down! This Versioned WPAR technology lets you run AIX 5.2 or AIX 5.3 inside an AIX 7 on Power7 Workload Partition (WPAR). You simply get the source AIX up to the required level (which you should already by running), then take a mksysb... [More]
Update: The developers and the manuals call this Load Sharing but most people think it is called Load Balancing. Perhaps, balancing gives the wrong impression of fine grain packet by packet balancing where we actually have higher level, cruder splitting of the work with Sharing. Below I use the word Balancing but mean Sharing. I have got a few questions recently on how to set this up as there are announcement with near zero information on setup, the configuration needed and a worked example. So here goes. For a long time now we have had SEA... [More]
Seasonal Greeting. My family decided to give me a Kindle e-book - Wow! So after the usual experiments with reading a book, playing with the web browser via WiFi, I then thought; Could this help me at work too! So reading up I noted it fully supports PDF format files and the IBM Redbooks come in PDF. So a quick download over USB cable and I can read them easily enough in landscape mode. As part of Advanced Technical Support, I am expected to "know everything" and over the past 10 years I have read all the POWER4, 5, 6, 7 machine... [More]
Shared Storage Pools is the next big thing to owed systems admin time and boost flexibility for Power Systems, PowerVM and controlling SAN disks from the VIOS and HMC. I will not go on about SSP here but I particular like the fact Live Partition Mobility even with SAN disks is ready to go with SSP and there is no need to reZone the SAN disks. To start using the new and improved SSP, you need the latest Virtual I/O Server (VIOS) - the version name is a nightmare! Who ever thought VIOS 184.108.40.206 FP25 SP01 with iFix was a sensible name for a... [More]
The below URL takes you to the top of the Systems Director 6.3 online documentation http://publib.boulder.ibm.com/infocenter/director/pubs/topic/com.ibm.director.main.helps.doc/fqm0_main.html As a rule I use Firefox 3.6.24 all the time for my browsing as it works well for Systems Director and Hardware Management Console (HMC). Later Firefox versions have "variable" results which re frustrating and that just slow me down. The Firefox developer when mad and got to version 8 suddenly over what appeared to be a few weeks but have realised... [More]
So a long download of about 7 hours for the 1.9 GB but a reasonably quick install. Fresh AIX 6.1 TL6 and service pack 6 installed. See my Update below for a problem with this AIX level. Prepared a /database filesystem for the DB2 database. The Pre-Install Utility told me to fix some file system sizes, more paging space and ulimit - good stuff. The Installer worked fine. The CIM Server install seems to take for ages at the start! It then refreshes the Common Agent, installed the default "managed" DB2 database invisibly behind the... [More]
IBM Systems Director 6.3 Arrives Early Yes, you read that right - it arrived earlier than the date in the IBM Announcement - a free to use unexpected Xmas present from IBM. I have never heard of an early delivery before - perhaps I am getting to old and cynical :-) The Base Server download for AIX is a larger 1.9 GB file (was 1.3 GB for 6.2) but that includes includes AEM,VMControl (and Service and support manager but we probably don't need that as we have the function in Power Systems via the HMC). They all get installed in one go but you... [More]
I thought I should summarise the long eleven part Local, Near & Far POWER7 Affinity series. 1) Placement: Find out the layout of your boxes CPU and RAM and if the RAM is evenly distributed across available DIMMs Find out the placement of your Virtual Machines (LPARs) with lssrad -av - or - topas -M 2) SMT4 : Expect POWER7 SMT4 CPU use to “look” different POWER5 & 6 have two equal threads POWER7 shuts down threads 3 & 4 and even thread 2 - when there is not enough processes running. 3) Entitlement : Only set minimum Entitlements,... [More]
At the Miami and Copenhagen Power Systems Technical Universities, I covered what we knew about the next release of Systems Director (6.3) planned for 16th December 2011. One of the hot topics was High Availability using disk replication for the embedded DB2 database for active:passive fail-over. It turns out this feature is not included with Systems Director 6.3 release - sorry about that. The good news, at least, is that this feature is in development and working for the next release of SDMC, which is based on Systems Director 6.3... [More]
Below is from your Power Systems, Advanced Technical Support team in Europe (EMEA) with lots of input from many people.
We find many people are over optimistic and making assumptions - which can catch them out - we learnt the hard way too.
Don't Assume 1 - The same boost as last time
It may be that you migrated from 2Mit to 10Mbit and saw approximately a 5 fold increase in performance.
Similarly when you went from 10Mbit to 100Mbit, and from 100Mbit to 1Gbit; you saw... [More]
I just realised that I got help from the AIX developers to explain the output of the mpstat -d command for my POWER7 and Affinity Technical University sessions in Miami and Copenhagen that I never passed on to every one. In an earlier blog we examined some mpstat columns but skipped others. The nearly undocumented mpstat stats are: S0rd, S1rd, S2rd, S3rd, S4rdand S5rd. In the AIX manuals it states: S0rd = The percentage of thread re-dispatches
within the scheduling affinity domain 0.
And likewise for the other numbers - but what does... [More]
I have been using Shared Storage Pools phase 2 (SSP2) on the beta test a lot recently and it works well - I am very impressed. One key side effect of SSP2 is that it really makes Live Partition Mobility (LPM) very simple and safe. But then I hit a problem that stumped me - nothing to do with the SSP2 technology - it was just that I in the Advanced Technical Support group have got rusty in setting up and using LPM. The first problem that most people hit is that the source and target Power machines must have the same LMB size - the what??... [More]
Active Memory Deduplication was announcement on 12th October and available on 14th October but there has been a little confusion on: what you need, how you install it and run it and how it works? This blog will attempt to demystify this interesting new Power Systems feature. This is one of many features to reduce the memory foot print and so reduce costs for POWER and AIX logical partitions. So far we have: Workload Partitions - reduce the memory used by many copies of AIX to just one Global copy and applications installed at the Global... [More]
The officials words I was sent: Starting on November 13, 2011, each IBM client accessing Fix Central (whether through their employees or other authorized representatives) will require an individual IBM ID to download fixes for a limited number of additional product areas (including AIX and VIOS). This requirement will be expanded to additional products in the future.This requirement will be expanded to additional products in the future. The registration process will be quick and simple and will provide users with a customized experience to... [More]
I have been wondering why the lower end POWER7 machines have local and far memory and not local and near. Perhaps you wondered too! Well at the Miami Power Technical University, I got to talk to Dr Joel Tendler (IBMer) and a POWER7 processor guru and put the question to him. He covered this sort of architectural topic in his presentation at the event and I learnt a lot in this area by listening to the "master". Below is some background and the explanation too. The POWER7 chips has two memory controllers for maximum performance but... [More]
Finally, I have the types of memory by POWER7 model double checked. I refreshed the table in part 1 but thought I should make sure every one sees the final version so I have not mislead people. Only the Power 770/780 and Power 797 have Near memory. All the smaller machine operate a Local memory meaning on the same same POWER7 chip and Far memory for any access to another POWER7 chip's memory.
The Hypervisor makes the virtual machine (LPAR) placement decisions and changes during DLPAR. The Hypervisor is part of the Power Systems Firmware. The POWER7 machines first arrived in the early months of 2010. Since then we have had a lot of field experience with the larger machines with large configurations with large applications and tens of thousands of processes running and in particularly the machines with all three layers of memory - which are the Power 770, Power 780 and Power 795. From this experience, the POWER developers have... [More]
After you have started and used your virtual machine (VM) for a while, you may decide to change its size using a Dynamic LPAR (DLPAR) change from the HMC (or SDMC or IVM, of course). This has virtual machine placement implications. When shrinking your VM, the hypervisor will decide which CPU or memory (LBM) to release and it might not select what you think is the obvious choice. When enlarging your VM, we might thing there is an obvious way to grow in a balanced way but we can't see: 1) where physically our virtual machine is placed in the... [More]