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
*** STOP PRESS *** - See the update in red at the bottom.
I was asked this lots of times at the recent POWER Technical Universities in Orlando and Athens.
Compared to a low numbers of local disks
The LUNs on a SAN disk subsystem with caching are very fast - even a simple test like AIX install times have halved. In addition, you don't have to fiddle about with stripping AIX Logical Volumes across disks or retro fit this to rootvg Volume Group filesystems after the install.
Compared to a... [More]
IBM announced lots of Power Systems software yesterday but the official announcements are pretty thin on the details. I have many Twitter tweets asking "What the heck does that all really mean?" and the official statements are marketing messages and not technical information like:
How do you get that working?
What are the pre-reqs?
What are the actual commands?
What does the Graphical User Interface look like?
How does that help me as a System Admin person?
I regularly get asked to run a demonstration for IBM Systems Director but that is a time consuming business for both me and the audience. Especially, when you can find out every thing that I know from the comfort of you own office or even home office plus Stop, Replay and Pause via YouTube videos. So here is a reminder and hopefully a page I can point to when I next gets asked.
ISD63 Workshop 1 Techie Intro... [More]
The latest Versioned Workload Partition (VWPAR) Version 1.1.2 is available but largely secret!
With this update I get on my AIX 7 virtual machine, in which I have installed both AIX5.2 and AIX 5.3 support:
# lslpp -L | grep -i vwpar
vwpar.52.rte 18.104.22.168 C F AIX 5.2 Versioned WPAR Runtime
vwpar.images.52 22.214.171.124 C F Versioned WPAR 5.2 Support
vwpar.images.53 126.96.36.199 C F Versioned WPAR 5.3 Support
vwpar.images.base 188.8.131.52 C F ... [More]
Most AIX system administrators use: smitty tcpip to add a hostname, IP address, network mask, gateway and DNS server setting to get the virtual machines (LPAR) and AIX on a network. And as a side benefit so we don't need to use the ghastly VTERM console any more as ssh or the dreaded unsecure telnet (just don't do it) can now be used - as the root user:
# smitty tcpip
Minimum Configuration & Startup
Use DHCP for TCPIP Configuration & Startup
When I log on to my home machine being AIX,of course, and type hostname I get:
nag@blue:/home/nag$ hostname -s
I get this because when I set the hostname in smitty it looks like this:
* HOSTNAME [ blue.aixncc.uk.ibm.com ]
* Internet ADDRESS (dotted decimal) [184.108.40.206]
Network MASK (dotted decimal) ... [More]
I had better point out that any performance tool of AXI command in a POWER Virtual Machine (LPAR) can only see its use of the Physical CPU, the size of its own CPU pool and (if Monitoring is switched on at the HMC), it has a number of the CPU use by "Other LPARs" use of its own CPU Pool. nmon gets these numbers by default and the nmon analyser graphs this data in the LPAR tab - this assumes its a Shared CPU LPAR. If it is a dedicated CPU LPAR then it can't get any of this Pool data and there is no LPAR tab in the nmon... [More]
I regularly get asked a question like: I have 4 months of data from 25 machines and have to develop a Capacity Planning model to size these LPARs on to new machines but I am having problems with having so much data. What can you recommend? We need graphs of
CPU compared to Entitlement
CPU Physical CPU use
Maximum real memory use
Sometimes this data is needed as input in to the Workload Estimator tool or Server Consolidation tools.
The answer is "it depends" and there is no Rule Of Thumb - IMHO.
The 2 times ROT is very old school and for small servers where peaks could really run out of RAM fast and hurt.
The worst I saw was 6 times but that was OS guys and RDBMS guys and app guys all said 2 times ... each!! and then the System Admin guy just added them up not realising it was the same 2 times! Basically, bonkers and they used 2% in the end.
With machines with large memory, say starting at 64 GB, the memory demand... [More]
When you install Linux on an IBM POWER processor machine (Red Hat, SUSE or now includes Fedora), you then need to add the IBM supplied additional RPM packages. These give you a whole bunch of useful tools like HMC comms so you can Dynamic LPAR change and LPM, diagnostic tools, and configuration listing commands. Plus more importantly nmon :-) The repository allows you to update your packages as new versions become available and to benefit from fixes and additional functions. Without these you don't get the full Power... [More]
The fifth POWER Ask the Experts is a one day customer technical event in the UK which ran in Manchester and London on 15th/16th July 2013. It proved to be a very popular free event. We had well over a 100 people attend which was a mixture of customers, a few Business partners and some IBMers.
10:00 - Power Systems Update - Pat O'Rourke: Austin Briefing Centre, USA Download 22MB .pdf
11:15 - Performance Best Practices with POWER7 - Nigel Griffiths, ATS Europe ... [More]
I have tried to get permission to pass on these numbers publically but got no answer at all. As these are facts rather than opinions, I see no harm in them. So I will work on the old theory: "it is easier to ask for forgiveness than permission" ... here goes.
The AIX Virtual User Group often asks a few questions as part of the registration process for the next webinar session and it generates fascinating statistics from real POWER and AIX users.
The people that join the AIX Virtual User Group are... [More]
Following on from my previous AIXpert blog on 1st July 2013 - "Core files filling important filesystems? Want email alerts about each core dump?" it was pointed out to me by AIX guru Mathew Accapadi that we can for many years use the ODM and AIX error reporting framework to send emails on the generation of core files. See the previous blog on how to force the core files to a particular directory - and not allow them to fill up important system directories. On the alternative reporting method see below:
Check out the... [More]
I got asked these questions recently and had to go look the subject up ... again! I seem to have forgotten some of the details and then I thought I would use some new features of AIX for the second part. In the distant past there was various way to stop core files being dumped in to the current working directory of the program that failed. In AIX 5.3, AIX 6 and 7, the "chcore" command does all the hard work for us by letting us
Choose a specific directory for core files - which is best in it own filesystem so it... [More]