I think it's 32 ops per channel, and the DS8000 can handle it. Since you are using dynamic PAV, I would have somewhere in the range of 8 to 16 locals per LPAR, but be sure to balance them across the two sides of the DS8000 for maximum throughput. There should be no problems with multiple locals per volume whether from the same and/or different LPARs. In fact, if you are using the DS8000 feature to stripe volumes across RAID groups, then each 1113 cylinder segment of the volumes will be on a different RAID group.
>>> Don Williams <donb...@gmail.com> 1/21/2010 1:18 PM >>> We only have four "DASD" FICON channels from each z10 (2). So all LCUs share the same eight channels (four from each processor). Each FICON channel can handle multiple concurrent I/O's (FICON handles eight concurrent operations?). I don't know how many concurrent I/Os a DS8000 LCU can handle. Would it be 64 (2 processors x 4 channels/processor x 8 operations/channel) or some lesser number? If it 32/processor, then what I am worrying about? -----Original Message----- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Ron Hawkins Sent: Thursday, January 21, 2010 12:05 PM To: IBM-MAIN@bama.ua.edu Subject: Re: PAGE datasets -- few large or more small Don, At a guess you probably have eight channels per LCU, and your volumes are configured on RAID-5 with 6+P+S or 7+P. In terms of potential parallel IO that makes eight locals look really good as a starting point for handling your peaks. If you have more paths and array groups then you can always have more than eight locals. You can use Custom Sized Volumes to allocate many, small volumes for Locals, or with Dynamic PAV you can put many small locals on one volume - one volume still has eight channels and 7 or eight underlying HDD. Note that the number of HDD is important for Page-ins, as they are usually cache misses. EMC and HDS customers can use Permacache or FlashAccess to create cache-locked Page Datasets for better-than-Flashdrive paging performance. Ron ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html CONFIDENTIALITY/EMAIL NOTICE: The material in this transmission contains confidential and privileged information intended only for the addressee. If you are not the intended recipient, please be advised that you have received this material in error and that any forwarding, copying, printing, distribution, use or disclosure of the material is strictly prohibited. If you have received this material in error, please (i) do not read it, (ii) reply to the sender that you received the message in error, and (iii) erase or destroy the material. Emails are not secure and can be intercepted, amended, lost or destroyed, or contain viruses. You are deemed to have accepted these risks if you communicate with us by email. Thank you. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
