AIX

Hello,

My first post to the Unix forums, thanks for having me!

The division of the company I work for uses a xseries/redhat/VMWareServer
solution to make sure that we keep hardware overhead low and use our machines to as near capacity as we can. These boxes are Intel with usually
dual or 8-way processors, more specifically (x345,365,340..).
All the boxes that run redhat/VMwareServer host at least 5 other virtual servers
for varying division functions. Most of them are domino boxes..

My question is this. I have heard that there is virtualization built into the
OS and harware for AIX, and am wondering if that is a significant performance
gain over what we use to justify moving to AIX and pSeries computers, or Blades with POWER5. Is virtualization the lpar technology that is spoken of on ibm's website?

Also, I have a 7044-170 workstation that I bought to experiment with, but it has no path upgrade for using more than one processor. Should I look at finding something like a 7044-270 which can go more than one to really be able to take advantage of lpar and virtualization? or can any box running AIX be a good herald of its abilities when trying to compare it versus another OS for purley tangible reasons? or only server class hardware?

If these questions are posted in the wrong section, or any other faux pas made, I apologize.

thanks greatly.
Mack

OMG, where to start.

Performance gain over hardware cost - pSeries hardware costs a lot more than the PC stuff you have.
Blades are not power5, so cannot run virtualisation (see below). Given the hardware constraints of a blade it would be pointless.
pSeries virtualisation is not the same as LPAR

LPAR (Logical PARtition) is physical partitioning of a system, so the hardware takes care of the resources that make up the partition and then you just install AIX or Linux to the partitions you have devided the hardware in to.

Say you have 2 processors, 2 disks and 2 ethernet adapters - you can have 2 LPARS each with one of each resource. So you have 2 fully functional instances of AIX running on the same machine, without the VM bloatware running underneath.
If you have 64 processors, 1000 disks, 50 network adapters.... think of the possibilities...

The virtualisaton bit is a means of configuring lots of the system to one LPAR then running AIX VIO (virtual I/O) on thet LPAR which then allows you to share those (I/O) resources among other LPARS, either in whole or in part. For example an ethernet adapter shared from a VIO LPAR can be used by several other LPARS.

You can also use DLPAR (Dynamic LPAR) to move resources between active LPARs - cool huh?

With micropartitioning you can devide a CPU into 100 and so configure a LPAR with as many percent of a processor as you think fit - even cooler!

Oh, and you'll also need an HMC for LPAR, DLPAR, VIO. An HMC (hardware management console) is a PC running a dedicated release of some form of Linux thats whole purpose in life is to manage the hardware configuration of the pSeries machine.

So not anything like VM but you can achieve a similar effect - you could just buy into x86 blades and continue with the VM / Linux thing and maybe reduce the footprint but the cost of hardware is questionable against the xSeries machines.

You need power4 hardware (and an HMC) for LPAR / DLPAR and power5 hardware (and an HMC) for LPAR / DLPAR and VIO, so even a 270 will not cut it. You'll need a power4 (p6xx) or a power5 (p5xx) machine if you want to have a play - some p6xx machines like the p620, p660, p680 and maybe others don't have power4 technology so take care, aim for one with an odd second character to be safe: p610, p630, p650, p690 and don't forget the HMC.