Ed, Paging and Spooling I/O uses "seldom ending" channel programs for good performance. If any other I/O happens to that device, it interrupts the paging or spooling channel program, decreasing performance. Since you have noticed that you need more page space, you must be doing more paging - hence you may not want to interrupt the paging I/O channel programs.
In z/VM 430 (until z/VM 510 or 520, not sure which) IBM included small page and spool areas on the xxxRES volume to complete the installation. Those were not really meant as permanent production page and spool areas (and that fact *could* have been better documented). I suppose that if you have low spool activity, and can accept the reduced performance, it would be OK to leave spool on the res pack. But "best practices" would be to move page (and usually spool) off to their own DASD (certainly not sharing PAGE and SPOOL on the same DASD as their seldom ending channel programs will compete), with nothing else allocated on it. At least not anything that's used when your production load is running. DASD is getting cheaper, people are getting more expensive. It's a matter of where you want to spend the dollars. Mike Walter Hewitt Associates The opinions expressed herein are mine alone, not my employer's. 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.
