I've always seen it as a recommendation not to fill AUX above 30% (or 25%, lets not quibble) for best performance. Generally would equate to the same thing in practice, but I've never specifically seen it as a disk (aka "dataset") recommendation.
As such, I always try to keep the AUX highwater mark at 30%. This means (for me) the same number of total slots. Although I always seem to wind up adding more anyway. However ... it is reasonable to suppose that this recommendation came about because of ASM algorithm design that may well have been predicated on the limitations imposed by SLED. See Steve Samsons post from Sept 1997 "There is another implicit threshold, namely an occupancy of 30-35% at which ASM stops trying to allocate contiguous slots for multi-page transfers. This may not be a performance problem on the EMC box, but ASM does work harder and the channel programs become less efficient. For best results, try to keep the occupancy at less than 35% most of the time." With the newer disk controllers, this may have all gone out the door, and maybe ASM *can* tolerate higher occupany rates. Greg is probably the only person to answer that one - maybe Jim as well. > > I am referring to the *recommandation* to not fill a pageds more than 25%. > AFAIR this recommandation dates from the 3380 era. > > My question is, is this ROT still correct for large 3390-09 pageds (and was > it still correct for 3390-03). > > If I replace a couple of (25%) filled 3390-03 pageds's with 3390-09's, > should I keep the total space occupied for a max of 25% or could this value > be raised, so I need less pageds's? ---------------------------------------------------------------------- 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
