> -----Original Message----- > From: The IBM z/VM Operating System > [mailto:ib...@listserv.uark.edu] On Behalf Of Michael Coffin > Sent: Thursday, August 20, 2009 7:43 AM > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: z/VM mode LPARs > > Hi Rob, > > I'm inclined to agree with you re: virtual CPU count should not exceed > physical CPUs - since the maximum number of ACTIVE virtual CPUs can > never exceed the total number of physical CPUs. Thanks for the > comments, I think I'll cut that number down accordingly. :) > > -Mike
I can only think of one possible reason. That would be when a system only has a single engine. You might want to define two virtual CPUs so that if something "hangs up" (spin loop?) one virtual CPU, you might be able to get work dispatched on the other virtual CPU in order to do problem diagnostics and recovery. I don't know as much about Linux on System z, but I have had this sort of thing happen on z/OS when a high priority task basically locked up the CPU. -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * (817)-961-6183 cell john.mck...@healthmarkets.com * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM
