Re: SWAPGEN

[Rich Smrcina]

The biggest benefit of z/VM is to virtualize resources as much as possible.  Dedicating a resource to a specific guest is a big waste and benefits one to the detriment of all the rest.  It would be much better to allocate all virtual disk swap for the Linux guests, then allocate the disk that would have been dedicated to swap as page space.  That way everyone wins. Scott Rohling wrote: Maybe --  but having a real disk (and setting an alert for that) helps isolate the issue to a single guest rather than affecting critical shared resources (in this case memory/paging) when a guest starts swapping more than normal or than it 'should'. I like the idea of having a 'failover' swap area on real disk -- whether you have a single VDISK or 2 prioritized ahead of it.  I guess whether it's waste of resource depends on your POV..  But your point is taken.. Scott On Wed, Apr 29, 2009 at 4:42 PM, Barton Robinson <bar...@vm1.velocity-software.com> wrote: giving real disks to swap is a real waste of resource.  It is much better to take the "extra disk resource" that you allocate but never want to use, and assign it to z/VM paging to enhance your paging subsystem.  Then define two vdisks for swap, prioritize them, and set an alert when the 2nd disk is being used. Martin, Terry R. (LOCKHEED MARTIN Performance Engineering/CTR) (CTR) wrote: Hi   I am using SWAPGEN to define by z/Linux VDISKS I also want to define a real disk for swap. My question is can I use SWAPGEN to define a swap on real DASD? If you have an example of the control card syntax to accomplish this that would be great?     //Thank You,//   //Terry Martin// //Lockheed Martin - Information Technology// //z/OS & z/VM Systems - Performance and Tuning// //Cell - 443 632-4191// //Work - 410 786-0386// //terry.ma...@cms.hhs.gov <mailto:terry.ma...@cms.hhs.gov>//   -- Rich Smrcina