Our MONDCSS grew, perhaps too large, while fighting this type message a long time ago. Once the problem was resolved, we didn't attempt to back off the changes we'd made, and the large size doesn't seem to hurt anything at the moment. I know that ultimately, making the segment larger was not the answer to the problem at the time, either.
Also, Mr. Nunsford says hello. -- Robert P. Nix Mayo Foundation .~. RO-OE-5-55 200 First Street SW /V\ 507-284-0844 Rochester, MN 55905 /( )\ ----- ^^-^^ "In theory, theory and practice are the same, but in practice, theory and practice are different." On 3/30/10 12:57 PM, "Eginhard Jaeger" <e.jae...@ch.inter.net> wrote: > There is no single 'right' MONDCSS size for all systems: it's about > performance, > so 'it depends'. The MONDCSS has to be large enough to allow the CP monitor > to place all the monitor records you told it to collect in that storage > area. Since > most users just go and enable whole domains, it's the domains generating the > largest > number of monitor records that one wants to watch. For sample records that > is, > on most systems, the I/O domain, where you could end up with tens of > thousands > of devices already years ago when I still worked with VM. Be aware that the > monitor will create a device activity record 3 of 268 bytes and a cache > activity > record 4 of 264 bytes for each DASD, and they must all fit simultaneously > into > the MONDCSS, together with all the other monitor records. > (And, as mentioned in another append, the default SAMPLE CONFIG size is > often too small for so many devices and has to be made larger.) > > But there's one general rule that has not yet been mentioned in this thread: > don't > let the MONDCSS overlay the storage of the virtual machine that is doing the > data collecting, in this case PerfKit, or it will not be able to use it. > > While your MONDCSS looks VERY large to me, I'm admittedly out of date as > far as current I/O configurations are concerned, and you apparently ended up > with it for a good reason, after a trial and error phase with smaller sizes. > Can you tell me the number of I/O devices that your VM sees and is > collecting > data for? > > Eginhard > >> ----- Original Message ----- >> From: "Bill Munson" <william.mun...@bbh.com> >> >> That does not look like it is large enough. >> >> here is my definition >> >> MONDCSS CPDCSS N/A 08000 0FFFF SC R >> >> It can work for a while but if the segment is not large enough it will >> soon fail.
