> There is no good recommendation how to set up a good paging > configuration on a modern DS8800 device, nor does it explain the > consequences of Hyperpav and WLMPAV set to NO in relation with OA32453 > where ASM is still building a " I/O infrastructure" that utilizes > Hyperpav. Nowhere is explained what this infrastructure looks like. From > conversations with Greg Dyke when he was the expert in that area, I know > that in the WLM managed PAV environment ASM reserved 2 access paths to > each page dataset, resulting in 2n-1 aliases dedicated to a paging > volume. Is this still done so in the Hyperpav situation?
There is no dedicating of aliases in the Hyperpav situation, because a Hyperpav alias is bound to a device only for the duration of one I/O operation. ASM still does at most two concurrent operations to a page data set (the normal chain of operations for that device, and possibly one concurrent single page read). So you still need multiple page data sets in order to get much concurrency, and if you want concurrent reads, you need to have the good fortune to have those the data for those reads to be distributed across the multiple data sets. The recent z/OS development investment in improving ASM performance has been in the support for paging to flash memory on the new EC12 processor. ASM can do many concurrent operations, and setting up the configuration is much less complex than page data sets - all you need to do is decide how much flash memory to assign to each logical partition. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
