Wednesday, September 23, 2009

LPAR information

So I thought LPARS started back in the 1980's. Apparently they started back in the 1960's, who knew :)

Here is an email I recieved from a reader of my blog:


Here’s the response I got back from the mainframe folks at IBM. Pretty interesting history…virtualization/lpar’s can be traced back to 1960!

In early 1960, IBM used an internal tool call CP-67 to create virtual systems to test S/370, a predecessor of z/OS. The tool eventually became a commercial product in 1972, VM/370. After many iterations of VM/370, in the early 1980s, Poughkeepsie baked the assembler code of VM into "machine code" (we now call it microcode) such that it ran much closer to the hardware.

This was to reduce the already single digit overhead of VM and create LPARs at the machine level as opposed to create LPARs at the OS level. So the LPAR code in z and p today can trace their genealogy to CP-67. If I equate virtual machines to LPARs, then the use of "LPAR" really started in the 1960's when CP-67 was used internally in IBM as a test tool. Commercially, LPAR started in 1972 when VM/370 was announced and LPARs were created at the OS level. LPAR at the machine hardware level started in the late 1980s when Poughkeepsie shipped 3090 that had the ability to configure a physical box into multiple LPARs.

--Removed PII data as you never know who will read this!

1 comment:

Jerry Rhoads EMIS said...

Sounds likethe evolution that is taking place with VMware. Testlab to baked in.