>To be precise: ASM reserves 2 exposures *per pagedataset* not per >volume (i.e. 2n-1 Aliasses per volume), since/so you can allocate more >than 1 pagedataset on one volume. We do so to fill 3390-9s and -27s with >pagedatasets.
I beg to disagree. :-) HiperPAV works on a per-IO-basis in the hardware, so ASM cannot 'reserve' an exposure (anymore). HiperPAV is for faster I/O turnaround and for reduction of IOS queuing times by giving another SSCH another 'exposure'. No SSCH, no HiperPAV usage. If no I/O is started because ASM knows there is one outstanding (as was the case in the past) then HiperPAV is effectively not used. Other than for the second case that Jim Mulder had detailed in the past. Hence my question if that is still true or if ASM now starts as many IOs as needed to get paging requests filled. Barbara ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
