I can't tell you the specifics about IFL's. I don't think it really matters but I could be wrong. Z machines have multiple CPU's that are the same. You can pay for the CPU's you want to use in the box. IBM disables those that you don't pay for. As an incentive to buy z architecture, IBM will allow you to pay a reduced rate for some (not all) processors E.g. IFL, zAAP, zIIp and ICF. IBM calls these specialized processors and they only allow the specific workload type.
As for disabling instructions, I don't think it restricts z/OS. It probably makes z/OS unusable when running on that CPU. If you somehow get z/OS onto an IFL, then it will most likely fail. Just a method to force you into paying for what you use. It's been many year's since I actually did anything with hardware so I don't know how CPU's are allocated any more. I thought that LPAR management doesn't allow you to specify specific CPU's. I thought you simply specified xx% of x IFL CPU's and xx% of 2 CP CPU's. As for adding / reconfiguring CPU's, I think IBM can do this remotely with a dialup to your machine. Jon Perryman. ----- Original Message ----- > From: adarsh khanna <adarshkha...@yahoo.com> > > I am starting to learn about Linux on System z and was going through redbooks > and other material available on IBM website as well as on google to get > details > on how is a mainframe core characterised as IFL. > > For IFL, I came across "This is a normal processor with one or two > instructions disabled that are used only by z/OS". > Please can someone help me understand : > > 1) Is the disabling of instructions done via micro or millicode? > 2) How does diabling few instructions restrict z/OS from running on IFL? > 3) Each mainframe book has MCM (multi chip module) which has 6 chips (latest > version) and each chip has 6 cores - when characterising each core as IFL is > it > possible to have only 4 cores in a chip as IFL OR is it possible to have 2 > cores > from 1 chip and 2 cores from 2nd chip as IFL? > 4) Once the system definition is complete and is executing production > workloads, > how is an IFL added to the system using the same book? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
