Russ, I think you've been misinformed....:-) It's still a good idea to
define expanded storage in an LPAR for CP to use even in z/VM 5.4
environments. This is especially true if you have over committed
storage, that is, the sum of the virtual storage sizes of all running
guests is greater than the size of the physical storage available in the
LPAR. In this case, CP will be forced to page, and it can page much
faster to storage than it can to DASD.
Ross Johnson wrote:
According to the z/VM and Linux SLES SP2 Cookbook, a ratio of 3:1 of
central to expanded storage is recommended, further justified at
http://www.vm.ibm.com/perf/tips/storconf.html
<http://www.vm.ibm.com/perf/tips/storconf.html>. Improvements documented
with z/VM 5.2 suggest that a maximum of 2G expanded is recommended, or
25 % of all configured storage. In my z/VM 5.4 and SLES SP2
implementation, I have been informed that expanded storage is no longer
required for z/VM with Linux guests. I tend to believe the latest change
in 5.2; a 4:1 ratio up to a max of 2G expanded. Any suggestions?
*Ross Johnson
*Sr. Systems Programmer
National Defence
Ottawa, Canada
internal email: [email protected] <mailto:[email protected]>
external email: [email protected]
<mailto:[email protected]>
Government of Canada
--
Dave Jones
V/Soft
www.vsoft-software.com
Houston, TX
281.578.7544
