Many of the newer z boxes come with Flash memory now, in 1.5Tb increments. Not sure if that is a separately chargeable feature or not. We configure the appropriate amount that shows up as SCM memory when doing a D ASM, and a drill down of D ASM,SCM. I'm though I read somewhere I saw that SCM gets preference for paging then regular local page datasets.
_____________________________________________________________________________________________________ Dave Jousma AVP | Manager, Systems Engineering Fifth Third Bank | 1830 East Paris Ave, SE | MD RSCB2H | Grand Rapids, MI 49546 616.653.8429 | fax: 616.653.2717 -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Allan Staller Sent: Monday, November 4, 2019 10:31 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: How display level of paging? **CAUTION EXTERNAL EMAIL** **DO NOT open attachments or click on links from unknown senders or unexpected emails** The number of local page slots provided need to support the virtual storage in use, so according to the algorithms posted below. Yes. If 30 TB of virtual is in use, about 30TB of page slots should be provided *(you can fudge things here at your own risk)*. Applying the 30% utilization rule to the local page datasets yields a 90TB slot requirement. As a matter of fact my local page slots *ARE* sized appropriately for the virtual storage in use on my LPARs, according to the algorithms stated. In my case, it is GB's, not TB's of slots that are required. One note; "days of yore" is late 80's / early 90's. I have not heard about any updates to the IBM ROTs since then. YMMV, -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Tom Marchant Sent: Monday, November 4, 2019 8:40 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: How display level of paging? On Mon, 4 Nov 2019 14:04:02 +0000, Allan Staller wrote: >IBM has generally recommended 2:1 virtual to real storage. I have >pushed this to 3:1 without major issues. >The paging subsystem should be configured accordingly page slots >approx. 3x available real. > >If you are actually going to be doing serious paging, (> +/- 20 pps) >the local page datasets should not be more that 30% utilized, so 9x >support real page slots is appropriate. Are you suggesting that an LPAR with 10 TB of real memory should have 30 to 90 TB of page space? If my arithmetic is correct, the minimum number of volumes that could satisfy that is between 545 and 1636 volumes of 3390 model 54. Do your systems follow the guidelines that you suggest? I think it is still true that local page data sets should be no more than about 30% full. IIRC the reason has to do with the probability that the system will be able to find full tracks to page out to. -- Tom Marchan ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ::DISCLAIMER:: ________________________________ The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. E-mail transmission is not guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or may contain viruses in transmission. The e mail and its contents (with or without referred errors) shall therefore not attach any liability on the originator or HCL or its affiliates. Views or opinions, if any, presented in this email are solely those of the author and may not necessarily reflect the views or opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of authorized representative of HCL is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any email and/or attachments, please check them for viruses and other defects. ________________________________ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN **CAUTION EXTERNAL EMAIL** **DO NOT open attachments or click on links from unknown senders or unexpected emails** This e-mail transmission contains information that is confidential and may be privileged. It is intended only for the addressee(s) named above. If you receive this e-mail in error, please do not read, copy or disseminate it in any manner. If you are not the intended recipient, any disclosure, copying, distribution or use of the contents of this information is prohibited. Please reply to the message immediately by informing the sender that the message was misdirected. After replying, please erase it from your computer system. Your assistance in correcting this error is appreciated. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
