On 2/3/06, Stefan Raabe <[EMAIL PROTECTED]> wrote: > Our VM will have 4GB, only one Linux Guest with 1 or max 2GB storage, 512MB > swap vdisk for this linux guest. > Remaining storage 512mb is for CP, some VM Users (TCP, administration users, > ...) and MDC.
And in that case it *is* a Bad Idea. When you lock pages with z/VM 4.4 they reside under the bar. Together with other stuff that needs to be under the bar as well, your system will not work if you lock more than 1.5G or so, thus creating even more contention. And since you mentioned you're using Performance Toolkit: depending on what you do it will actually also go for pages under the bar. Why don't you run Linux in LPAR when you are so certain that you want to dedicate part of your real estate to that server. Most z/VM installations find that allowing CP to manage the resources (with some help) is more attractive than doing it yourself by hand. Proper measurements can show you whether resources spent on VDISK or MDC are worth it or not. > Is there any advantage if some of the storage is used as expanded storage? Yes, in your configuration you should define expanded storage. It's for providing a hierarchy in storage management as well as a circumvention to reduce the impact of contention under the bar. Especially when the total active memory of your Linux server is getting close to 2G (and unless you do things, eventually the entire Linux virtual machine main memory will appear active to VM). 25% has been suggested as a starting point, but measurements should help you determine the right value. The right value depends a lot on what Linux is doing. And make sure to disable MDC into expanded storage as I suggested yesterday. Rob -- Rob van der Heij rvdheij @ gmail.com Velocity Software, Inc
