Art, Channels paths, ports, Front End Directors and ports are easy to map so that locals can be allocated across every possible path.
The missing part of most strategies is understanding the parallelism from the cache to the disk and array group. There are many schema available for RAID and wide striping, and path boundaries within the storage to take advantage of (or tie you up). Spend some time with your vendor to understand exactly what you have and how you can use it to maximize parallelism. For example on 2 chassis VSP you have two separate set of disk paths behind each control frame, so male sure you page datasets are spread across each chassis, either by way of the HDP pool definition or the parity groups you use in basic volume mode. Sorry for the Hitachi parlance, but it stresses the fact that you have to design for the hardware you are using. An EMC methodology will not be best practice for a DS8800, and an ESS methodology will not work on an Hitachi. With the relative inactivity of page datasets, I would suggest one uniform rule when tired storage is used would be to lock them into tier one storage. You don't want the empty slots migrated down to SATA or external storage when they suddenly get busy. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] > On Behalf Of Art Gutowski > Sent: Friday, January 03, 2014 10:09 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: [IBM-MAIN] Local Page dataset sizing/quantity ROT? > > Yes, how to maximize parallelism is the pertinent question. > > Let's assume for the sake of argument, DS88xx with no SSD. > Mix of 3390-3, -9, and -27; HiperPAV enabled, with DASD defined as SHARED > in the IODF, and some shared across Sysplex boundaries (understood this is > not utopian, but some customers do it, either self-managed or with the > assistance of MIM/MII). > > How do you spread that 100GB across the farm, assuming you have at least > 45 mod-3 equivalents? (If my math is not too far off, there's about 2.2GB of > usable page space on a mod-3). What would one avoid so as not to handcuff > HPAV? > > Regards, > Art Gutowski > General Motors Corporation > > On Thu, 2 Jan 2014 08:55:24 +0100, Vernooij, CP - SPLXM > <kees.verno...@klm.com> wrote: > >I agree, overall sizing is a minor issue: make sure there is enough, what > >does > 100GB more cost these days? > >The more important issue is parallelism. Make sure ASM can do mass page > outs if it needs to. Page in should not be >your problem I suppose. > >This brings in the missing info: what is your storage device? > >Why don't you have Hiperpav? > >The DS88xx are much more flexible than the ESSs. > > Kees. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email to > lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
