IBM has talked about the excess Share problem as well, see chart 23 in http://www.vm.ibm.com/devpages/bitner/presentations/vmup2011.pdf And we are working on it. I think an assertion that it happens all the time is a little overboard. Now that we understand the problem better, I can say everyone may be exposed, but not everyone will be affected. We have been asking for people to contact me or open a PMR if they see the problem and have data. No PMRs have been open yet. A PMR always makes it easier to prioritize. I don't understand why those that see it, refuse to open a PMR.
The idea that IBM is working on changing this behavior to get around too high default share settings, while creative, is fiction. I agree some share default settings are now too high for Linux environment workloads. In general, the experience has been that it is better for some of these SVMs to be too high rather than too low. I'll put it on the list to revist some of these and see if we can change where appropriate. The defaults are meant as starting points. As discussed already, there are some good papers out there to assist with the tweaking. And for some other products, such as VTAM, the defaults are wrong for 99% of the environments. Sorry, my failure to get changes made there. Bill Bitner - z/VM Customer Focus and Care - IBM Endicott - 607-429-3286
