CP is the only user of xstore. We have so little CMS activity, so all MDCACHE, what little there is, is in main storage. When using the VPARS product, MDC must be off for any disk that TPF uses.
Regards, Richard Schuh > -----Original Message----- > From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] > Behalf Of Nick Laflamme > Sent: Thursday, August 24, 2006 11:44 AM > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: Storage Configuration > > > Schuh, Richard wrote: > > We have been on z/VM 5.2 for 2 weeks and have seen the 2G > bottleneck disappear as expected. We have seen an ability to > run more users as our main benefit. We used to run into the > 2G wall with about 100 TPF guests. We have run as many as 132 > without complaints since 5.2 was installed. We did uncover a > latent demand for cpu time and regularly drive the system > over 85% cpu. > > > > Now that we have a baseline with our old configuration, we > are ready to try to tune our storage allocations and would > like some guesstimates of how it should be allocated. The > particulars are: > > > > Machine: z990 model 305 > > Storage: 56GB currently allocate as 30GB main, 26GB Xstore. > > Software: z/VM 5.2.0, Service level 0601+ > > Workload: 90% TPF testing, up to 132 concurrent TPF > machines ranging in size from 690MB to 2GB. These machines > are driven by CMS machines running scripts, so they are more > like batch machines than interactive. TPF acts more like > Linux than z/OS. > > > > Do the two Titans of performance (or anyone else) have any > ideas about how ought to allocate storage as our first try? > > > > How is your Xstore being used? Is it dedicated to TPF guests, > or is it > for some VM function, such as MDC? (My guess is, MDC might be > trumped by > caching in TPF and your disk subsystems, but the key word > here is "guess.") > > How are your paging rates, for that matter? > > I'm surprised by such a low ratio of Main:Xstore, but since > I've never > had TPF guests, what do I know? > > Nick >
