Probably only true if you have a good cache-hit-rate, but this depends on the box. PAVs will certainly help here if the box supports them and you have configured them.
Kees. "Jousma, David" <[email protected]> wrote in message news:<a90766b5039c59409110c92d47216f590677b...@s1flokydce2k322.dm0001.in fo53.com>... > Iosq? Really? This is raid dasd, isn't "slow" 3390-9's a thing of > the past? > > _________________________________________________________________ > Dave Jousma > Assistant Vice President, Mainframe Services > [email protected] > 1830 East Paris, Grand Rapids, MI 49546 MD RSCB2H > p 616.653.8429 > f 616.653.2717 > > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Staller, Allan > Sent: Monday, January 23, 2012 10:09 AM > To: [email protected] > Subject: Re: Going from mod-3 to mod9 > > <snip> > 1. We just had 3390-9's configured into our EMC box. This box also > contains 3390-3's. Given that the hardware is the same throughout and > all other things being equal, is there any decrease in response time on > the mod-9's? > </snip> > > 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. Multi-system > access will exacerbate this even more. > > <snip> > 2. I have a VSAM file (with extended addressability) that currently > spans 27 mod-3's. My plan is to move it to 10 mod-9's using IDCAMS REPRO > to back it up then doing a DELETE/DEFINE, (changing the SPACE parameter > from CYL(2500 150) to CYL(9500 150)), then REPRO from the backup. Am I > setting myself up for a failure? > </snip> > > I do not believe there will be an issue. Obviously, you already have all > of the SMS stuff in place. I would, however suggest REPRO from > "original" to "original.new" and after successful repro operation, alter > "original" to "original.old" and then alter "original.new" to original". > In this way, the original is always available for a momentary recover if > any problems are discovered with the target of the repro. > > 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 [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
