Is there is any benefit to using dedicated DASD vs minidisk with 5.2 on a z/890 ( No IOASSIST available)?
Ken Libutti CNE, CNI, SCSA, RHCT Asst. Director of Systems Services Broward Community College 225 E. Las Olas Blvd. 31/330 Ft. Lauderdale, Fl 33301 Phone: 954-201-7361 Fax: 954-201-7053 [EMAIL PROTECTED] Please Note: Due to Florida's very broad public records law, most written communications to or from College employees regarding College business are public records, available to the public and media upon request. Therefore, this email communication may be subject to public disclosure. >>> [EMAIL PROTECTED] 7/28/2006 12:53:04 AM >>> On Thursday, 07/27/2006 at 02:46 AST, David Boyes <[EMAIL PROTECTED]> wrote: > > > >Then again, if you have a z9, you probably don't much care. 8-) > > what about performance and CPU overheads (zVM) in processing I/O's, is > > it an issue? > > It (the difference between dedicated and minidisk I/O) is measurable, > but the impact is smaller on the z9 systems due to the increased > processor speed. > > I'm sure the Velocity folks will chime in with more details. I/O assist was only available with V=R and V=F guests while running in basic mode, so any improvement was limited to those 6 virtual machines. For a Linux farm, the vast majority of guests (V=V) never benefitted from I/O assist. And starting with the z990 there is no basic mode, so even the Big Six get no benefit. That, plus the removal of preferred guest support (V=R and V=F) from z/VM V5, the loss of I/O assist on the processor doesn't mean much. Alan Altmark z/VM Development IBM Endicott ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
