If the guest is a CMS user, SFS might be the answer. Regards, Richard Schuh
-----Original Message----- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of McKown, John Sent: Tuesday, April 25, 2006 9:11 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: 3390 Mod 3 verses 3390 Mod 9s > -----Original Message----- > From: The IBM z/VM Operating System > [mailto:[EMAIL PROTECTED] On Behalf Of Dusha, Cecelia > Ms. WHS/ITMD > Sent: Tuesday, April 25, 2006 8:03 AM > To: IBMVM@LISTSERV.UARK.EDU > Subject: 3390 Mod 3 verses 3390 Mod 9s > > I have a question that pertains to performance. > > We currently have 3390 mod 3 defined volumes. The customer requires a > larger mini disk size than what will fit on a 3390 mod 3. We > are planning > to create 3390 mod 9s for their larger mini disks. Would > someone explain > the performance hit that will occur by placing their data on a larger > volume. Maybe it is insignificant, but I seem to recall the > architecture > permits a limited number of accesses to the device. If there > are a large > number of users who require access at a given time, then the > users could end > up waiting for the device? > > Please advice. > > Thank you. > > Cecelia Dusha You hit it on the head. Without PAV (Parallel Access Volume) support, a single volume can perform only one I/O to it at a time. If you combine three highly active volumes onto a single volume, you will experience delays. My question would be: What is going onto this -9 volume? Why can't it be multi-volume? What "guest" OS will be using this volume (z/OS, z/VM, CMS, zLinux)? The only thing that I can think of is a really large CMS filesystem. But that is not sharable, so it is not likely to be a bottleneck. -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology This message (including any attachments) contains confidential information intended for a specific individual and purpose, and its content is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this transmission, or taking any action based on it, is strictly prohibited.
