As others have said - you don't need to change any guests for z/VM to utilize the additional IFL - it will do so all on it's own.
Scott On Tue, Jan 5, 2010 at 10:24 AM, Harris, Nick J. <[email protected]>wrote: > Hi Mike and thanks for the update. > > According to our performance product we do NOT need an additional IFL at > this time but it was included as part of the z10 upgrade so I wanted to > utilize it. > > Thanks, > Nick > > > -----Original Message----- > From: The IBM z/VM Operating System [mailto:[email protected]] On > Behalf Of Mike Walter > Sent: Tuesday, January 05, 2010 9:49 AM > To: [email protected] > Subject: Re: 2 to 3 IFLs > > Nick, > > Disclaimer: I'm not a performance geek. > > I presume that you believe that you need to add a third virtual processor > to each Linux guest's virtual machine definition (directory entry) for it > to use the added third real processor. That's not true. Unless > constrained in some way, CP will automatically spread the work of all > Linux guests across all the real engines to which it has access. > > Adding more virtual engines to guests can actually cause more thrashing > and overhead unless a performance management product clearly shows that > the multithreading supported by that guest real has a bottleneck of > backlogged threads tat could be dispatched on other engines. We have > three z/OS running happily with two virtual general purpose engines, while > CP spreads their work evenly across three real general purpose engines. > > Which performance product results have you been using to determine if the > Linux guests need an added virtual processor? > > And now I turn this thread over to the real performance geeks who will > happily point out any errors in my advice (which may just end up serving > to inspire debate and shared knowledge). > > Mike Walter > Hewitt Associates > The opinions expressed herein are mine alone, not my employer's. > > > > > > > > > > > "Harris, Nick J." <[email protected]> > > Sent by: "The IBM z/VM Operating System" <[email protected]> > 01/05/2010 09:32 AM > Please respond to > "The IBM z/VM Operating System" <[email protected]> > > > > To > [email protected] > cc > > Subject > 2 to 3 IFLs > > > > > > > > Hello All, > > We are upgrading our z9BC to a z10BC and increasing the IFLs from two to > three. I am planning on modifying the Linux guest definitions to utilize > the third IFL. Are there any performance issues or problems adding a > third IFL? I can?t imagine this would do anything but help, I?m just > checking. > > We are running z/VM 5.4 in support of Linux guests. > > TIA! > > > > Nick Harris > Lead Systems Programmer, Information Systems > [email protected] > Texas Farm Bureau Insurance Companies > P. O. Box 2689 Waco, TX. 76702-2689 > Phone 254.751.2259 > > > > > > > > > CONFIDENTIALITY STATEMENT: The foregoing message (including attachments) > is covered by the Electronic Communication Privacy Act, 18 U.S.C. sections > 2510-2521, and is CONFIDENTIAL. If you believe that it has been sent to > you in error, do not read it. 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. > > . > > > > > > > > The information contained in this e-mail and any accompanying documents may > contain information that is confidential or otherwise protected from > disclosure. If you are not the intended recipient of this message, or if > this message has been addressed to you in error, please immediately alert > the sender by reply e-mail and then delete this message, including any > attachments. Any dissemination, distribution or other use of the contents of > this message by anyone other than the intended recipient is strictly > prohibited. All messages sent to and from this e-mail address may be > monitored as permitted by applicable law and regulations to ensure > compliance with our internal policies and to protect our business. E-mails > are not secure and cannot be guaranteed to be error free as they can be > intercepted, amended, lost or destroyed, or contain viruses. You are deemed > to have accepted these risks if you communicate with us by e-mail. >
