"Staller, Allan" <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>... > Kees wrote: > <<snip>> > > AFAIK, No. > > > > BTW Why are you still doing VIO at all? > > It made a lot of sense when disk access times were 17-30 ms, but not > > with 3-4ms (Escon/Cache) or < 1 ms (FICON/Cache) > > > > Is this that simple? The fastest I/O is the I/O you don't do. With VIO > you have a good chance to keep all data in storage, depending on the > amount of real storege, your UIC and your paging. But in modern systems > I think you have a good chance to eliminate all I/O with VIO datasets. > <</snip>> > > Everything is relative my son! > > VIO only eliminates some of the I/O (associated w/allocation). Under the > covers VIO is a data windowing system backed by aux storage.
Don't think so. This used to be the case in the early days, when systems had 4 MB storage and keeping the vio window in storage could just be toleated. Today I a sure VIO paging will not be that dumb to page in and out while GB's of storage are available to keep the data at hand. So I state that with VIO the I/O is eliminated. Anyone from MVS Internals who can give the current state of facts? As for Ted's response that VIO overhead and fast Dasd are approacing each other such that the don't differ much in performance: I don't have figures to prove the opposite and I accept it if someone has measured this, although it surprised me at first hand. Kees. ********************************************************************** 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: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
