Shmuel, And a side bar - if the three 3390-3 are accessed from three different LPARs, then consolidating them will mean zero impact without PAV because MDA will allow concurrent IO to cache and disk.
Don't shoot me - it's an academic point. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of > Shmuel Metz (Seymour J.) > Sent: Monday, January 23, 2012 10:19 AM > To: IBM-MAIN@bama.ua.edu > Subject: Re: [IBM-MAIN] Going from mod-3 to mod9 > > In <45e5f2f45d7878458ee5ca679697335502e25...@usdaexch01.kbm1.loc>, on > 01/23/2012 > at 09:08 AM, "Staller, Allan" <allan.stal...@kbmg.com> said: > > >Beware of IOSQ! From the viewpoint of the Operating System, you now > >have 3 times as much data behind the actuator on Mod-9's as Mod-3's. > >If the Operating system *thinks* the device is busy, the IO is queued > >off the UCB and never even tried until it comes to head of queue. > > The relevance of that depends on the number of exposures. > > -- > Shmuel (Seymour J.) Metz, SysProg and JOAT > ISO position; see <http://patriot.net/~shmuel/resume/brief.html> > We don't care. We don't have to care, we're Congress. > (S877: The Shut up and Eat Your spam act of 2003) > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email to > lists...@bama.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN