Thank you to all who have responded. What follows is the latest feedback from the person tasked with fixing this problem:
Today we were able to re-allocate 512m of central storage to the Linux guests. This will place us comfortably below the 2gig available for VM. We performed this by a shutdown of the Linux guest, logging on as the user of the guest and specifying the new central storage value of (512m). We then re-ipled the Linux guest and noted 512m was now the new storage value. This however will not persist between IPL's. The z/VM USER DIRECT file in VM's directory must be edited and the associated values for USER changed to the new storage values. The question remains whether DIRMAINT will be used to make this change or xedit. We will wait for Bobby on Monday to determine what has been used to date. ________________________________ From: Mary Anne Matyaz [ Subject: Re: Performance problem Linux under Zvm "The real approach is to reduce the working set of the Linux virtual machines to fit in what you have available, instead of telling CP to think that it has 2 or 3 times as much. One way to reduce the working set size is to change the virtual machines into 512M plus 256M VDISK for cache. It is almost as fast (because VDISK is data-in-memory) but discourages Linux to use it as cache. It could also be that the Linux server did not really need 768M but someone just invented the number (or used this to run the GUI installer). If the 512M + 256M does not swap, you can probably lower the 512M and see where it goes." Rob, Say you inherited a few linuxes and they are webservers, file servers, etc, that are set at 768M, 1024M, even 1536M. How do you tell what the working set size is? Is the wss indicated on the perfkit paging screen a valid indicator? I can't necessarily get in to these linuxes either. :) Thanks, Mary Anne
