Thanks Jim, this is what I assumed now ASM does. My question is: how many concurrent I/Os will/can ASM do if it does a heavy dump? I have determined the needed slots and therefor the size of the 10 paging volumes. If I put 1 page dataset on each volume, ASM can do 20 concurrent I/Os. If I put 2 page datasets on each volume, it can do 40. How may are beneficial to ASM, given the fact, that we will have 12 Ficon channels to the DS8800?
Kees. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Jim Mulder Sent: Friday, November 09, 2012 20:26 To: [email protected] Subject: Re: Paging configuration recommandation on modern Dasd. > 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 ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
