Thanks Martin, As I said in my previous pageds question about the 4 or 64 GB maxsize, I am investigating the limits, but not necessarily implementing them.
Kees. "Martin Packer" <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>. .. > I've been following this with interest and have had to think about page > data set design from a different angle, which I'll come to towards the end > of this contri. > > The point about continguous slot allocation remains valid. There has been a > change, which I don't think materially affects this, round about the 1.2 > timeframe. Perhaps someone from Poughkeepsie can comment on what I've > tended to think of as "more aggressive slot harvesting". But I don't think > that makes much difference to the argument about utilisation. > > The second point is the "leave enough room to dump that large DB2/WAS > address space" argument. Actually, a fortiori, I'd say "leave enough space > to dump the whole of real storage". So that gives another "ROT" of "leave > free page space of about 1.5x the amount of real storage you have". > > Note: Both the "25%" and the "1.5x" ROTs are trying to simplify > probabilistic things (as always). So, you know in your shop what happens > when you fail the ROT. In the former case paging performance tanks. In the > latter it's a real bad news day when that 6GB DB2 subsystem dumps. (I've > seen the latter happen and it's not pretty - when you don't have the paging > space to contain it.) > > Also note: You don't really have to choose which of these two > considerations. Go for both. > > Which takes me back to my current client - who's asked me for metrics to > track. (I'd neglected to put the "25%" metric in, so thanks all for that.) > > Regards, Martin > > Martin Packer, MBCS CITP Martin Packer/UK/IBM > 020-8832-5167 in the UK (+44) (MOBX 273643, Internal 7-325167, Mobile > 07802-245584) > > "Las cosas de palacio van despacio" > > External Blog: > http://www-128.ibm.com/developerworks/blogs/dw_blog.jspa?blog=476 > Internal Blog: > http://barney.adtech.internet.ibm.com/pilot/weblogs/comments/[EMAIL PROTECTED] k.ibm.com > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html ********************************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. ********************************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
