AIX 5.3 within a Versioned WPAR - Just give it ago, it's easy!
nagger 100000MRSJ Comments (19) Visits (20658)
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 backup of the root volume group (rootvg) of disks and use that in the make WPAR command (mkwpar). You have to install the small LPP (means you have to pay for it) Versioned WPAR package - I use smitty installp and it takes nearly 20 seconds!!
The only problem area that I know about and come across personally are:
The customer brought their mksysb from their AIX 5.3 machine to IBM on a USB Memory Key as it was 5 GB in size - How things are changed from those bad old days of spending 2 days trying to match a tape drive technology and format so we could copy over data. I read this mksysb in to my Thinkpad and transferred it to my POWER7 machine in around 5 minutes - the customer then laughed as it took him 4 hours to get it to the USB Memory Key due to very slow networks and firewalls.
There are lots of options now for the file-systems, disks, rootvg disks and even adapters in WPARs - one rule is to just install in straight in to local file-system for the first attempt.
In this case, the AIX 5.3 source was from a pSeries S85 24 way (from memory 600 MHz RS64 PowerPC chip). At a very rough estimated rPerf of about 7 (there were no rPerfs in those days only the Rel.OLTP rating) - every single POWER7 CPU-Core is rated at 21 rPerf's each - Yes things have improved over the 11 years. Mind you, I have a soft spot for the S80 and S85 - that was the machine I first nailed the Sun UE1000 64 way machine in benchmarking running the Apache web server. Our 24 way out gunned the Sun 64 way by quite a large margin and at a lower cost.
Anyway, back to my Versioned WPARs. The Versioned WPARs mkwpar command took about 25 minutes - it could have been much quicker but it was disk bound due to me only spreading the LPAR across lots of virtual disks which were actually sitting on just 2 disks on the VIOS local internal SAS drives. Next time I will try harder with my disk layout to boost the number of real disks or SAN disk sub-system caching and get the mksysb under 5 minutes.
The command was simply:
So it installed the mksysb in the WPAR fine and the mkwpar command even reminds you of the command to start the WPAR at the end, and it starting in roughly 10 seconds with no issues. Of course, AIX 5.3 is not so far being AIX 7, so there is less work to do than for the AIX 5.2 case.
Next was logging on - arh!! We could not telnet or ssh to the WPAR as direct root access was switched off (a normal security hardening feature). The WPAR developers thought about this years ago, so we can use the "clogin" WPAR command from the Global AIX level to "sort of" locally login to a console without the network. Fortunately, the customer knew the root password but then had to do some fiddling as it had extra password secondary challenge response additions. They knew how to switched these off and after 5 minutes, we were in business.
Then we started trying all their applications and system admin tools - well the largish database was not brought with them but we could start a dumb database, backup tools and the like. We then hit one that would not work. It included a 32 bit Kernel extension - this was a tool that monitors and controls the batch tasks. Why such a tool needed a kernel extension is beyond me. Kernel extensions were much more popular 10 years ago - it was a method to work around an OS that did not have some feature. The problem with them was you need very high kernel internal skills programmer to write one and support it. Over the years, the AIX developers have add all the "missing" features into the OS directly, so there really is no need to them any more. The customer then said that the batch tool was "a well known problem" to them and it was not actually supported any longer!! They took the action to go and investigate if there was a 64 bit kernel extension that would possibly work in the WPAR or to use a different batch task monitoring tool.
I have yet to get my head around the double minded approach:
For the record, AIX 5.2 normally worked with Oracle 8 - that came with a 32 bit or 64 bit kernel extension. We can mount the 64 bit version at the Global AIX and the WPAR can use it. Of course, you need to ask Oracle about support - and not IBM (it is not our project so our opinions don't count).
It always amazes people when I show them that you just have to mount file-systems or place files at the WPAR root mount point or below at the Global AIX and the files are available within the WPAR. In our case, /wpars/wp09. We can use a Symbolic link or NFS mount and it works - just like magic. WPARs are very easy to live with.
Here are a few useful links in to the AIX manual for Versioned WPARs
The equivalent mkwpar command for using NFS based on a single mount point is
The -c means it is "checkpointable" - so it can WPAR Mobility to jump just the WPAR to a different Global AIX 7 on possibly a different machine.
Unlike LPAR Mobility which jump the entire AIX between machines. The reason this is one NFS mount point and not size of them is because the 5 lower mount points are within the directory of the first root one. Yes we have an NFS server with a hostname of "nfs" with a exported directory of "/nfs" - it is very simple to remember the name!
I hope this helps, you to give WPARs and Versioned WPAR a go. Don't forget plain WPAR are free with AIX 6 and AIX7 and have been out for many years now. Thanks, Nigel Griffiths