I agree. Then we would not have to reconfigure LPAR storage definitions when testing OS/390 and z/VM.
________________________________ From: The IBM z/VM Operating System [mailto:[email protected]] On Behalf Of Huegel, Thomas Sent: Wednesday, March 04, 2009 4:05 PM To: [email protected] Subject: Re: XSTORE Understanding that CP uses an algorithm that handles XSTORE as a preferred paging area the question arises as to why? Since XSTORE is just a piece of main memory the reason for it's existence is no longer that it is some cheaper slower memory that can be used for paging. I think we all look at setting up the hardware and defining XSTORE as a permanent definition. Is it time to change CP, perhaps adding a parm to SYSTEM CONFIG that says OK CP use 500 meg of main storage for paging etc.? In other words instead of making a hard configuration change lets just tell CP how much memory to 'treat' as XSTORE. -----Original Message----- From: The IBM z/VM Operating System [mailto:[email protected]]on Behalf Of Kris Buelens Sent: Wednesday, March 04, 2009 1:43 PM To: [email protected] Subject: Re: XSTORE Attaching XSTORE to a user: you can, but it is up to the user to do something with it, CMS doesn't use it at all, z/OS no longer supports it, and I don't know about Linux. To define some XSTORE fo CP is still a good thing if VM starts paging: XSTORE is managed differently than central storage. With some XSTORE CP has a better chance to select the best pages to page out. 2009/3/4, Michael Coffin <[email protected]>: Hi Folks, What value is there in defining XSTORE these days? Aside from the ability to attach XSTORE to specific virtual machines, wouldn't it be best to just make it all DPA and let CP manage it? Also, assuming you aren't paging much - is attaching XSTORE to a userid going to provide a VERY noticable improvement in performance (at the expense of taking it away from all other virtual machines, of course)? -Mike -- Kris Buelens, IBM Belgium, VM customer support
