Don't let the compile times scare you. It is long established that the zSeres processors are not the fastest on the market, far from it. What you gain by running on zSeries is extremely fast internal communications with Hipersockets and Virtual Switch, high I/O bandwidth (FICON and SCSI disk support) and the economies of scale of being able to run multiple middleware machines with only the license cost of the zSeries CPUs.
Will you be able to consolidate all of your x86 machines to zSeries? That greatly depends upon what is running on those machines and how heaily loaded they are. Measuring their current load (before and after) is important. You've touched on one of the best ways to run Linux for zSeries machines, cut back their virtual machine sizes to only what they need. For the most part, ignore that your Linux 'experts' tell you for memory sizes. Chances are they will de-tune your environment. Cut back their size to the point where they just start to swap, then bump it up a LITTLE. Vdisk swap is great for bursts of activity, as long as the swapping is not constant and high, you should be running just fine. Miller, Ila wrote:
We have SuSe enterprise linux 9 running on 6 zVM partitions. We are running VM in an IFL - one cpu on a z900. One linux is the clone copy that is pushed out to clone the other partitions. One linux clone is running a mail relay that isn't very busy. Three linux are running apache, tomcat, ant, cvs, and java. These are not in production yet and are not doing much of anything other than running all the applications. One linux is supposed to be a Tivoli Gateway, but we continue to have problems with Tivoli and Enterprise Linux 9. It appears a compile on any of the linux takes a very long time and compares to a Pentium III processor speed. Is this what we can expect running linux under zVM? We were anticipating we could eliminate 10 x86 servers at least. Even though we were given a deal on the IFL, if it cannot run 5-6 linux partitions, it does not make sense to add the overhead of maintaining zVM. One of the sys admins 'found a way to achieve the memory restrictions for a Linux guest and still allow Tomcat/java to run. There are a couple of kernel parameters that allow a process to malloc more memory than is phycisally on the machine, specifically /proc/sys/vm/overcommit_memory. We can use this and implement swapping to vdisk. By starting the guests with say 100 MB of RAM, we should be able to limit the amount of RAM used for file buffering. At the very least this should enable us to create smaller footprint guests in RAM terms. However, all that said, I'm still concerned we're trying to get Formula One performance out of a pinto. Are we going down the wrong path trying to run linux under zVM to eliminate all the x86 boxes we have? I would like to have feed back on what kind of performance we can expect to get out of a 1 cpu z/VM on the z900 IFL and how many linux can run there? Ila Z. Miller ___________________________________________________________ ___________________________________________________________ Health Care Information Systems University of Iowa Hospitals & Clinics [EMAIL PROTECTED] Phone: 319.356.0067 FAX: 319.356.3521 Notice: This e-mail (including attachments) is covered by the Electronic Communications Privacy Act, 18 U.S.C. 2510-2521, is confidential and may be legally privileged. If you are not the intended recipient, you are hereby notified that any retention, dissemination, distribution, or copying of this communication is strictly prohibited. Please reply to the sender that you have received the message in error, then delete it. Thank you. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
-- Rich Smrcina VM Assist, Inc. Main: (262)392-2026 Cell: (414)491-6001 Ans Service: (360)715-2467 rich.smrcina at vmassist.com Catch the WAVV! http://www.wavv.org WAVV 2006 - Chattanooga, TN - April 7-11, 2006 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
