> >>BTW: 27998 is *sometimes* optimal blksize. It depends on other dataset >>parameters. > > Sometimes? > When is it not? > The resource implications of 'large' block sizes have disappeared, except for > space usage. > There are some old utilities that still require 'strange' block sizes, but I > cannot see one bad usage of 27998, especially in Batch/TSO, as long as there > is no hard-coded one in the programme using the dataset.
For some fixed length records, 27998 (or half-track) would not be the most efficient use of the track.. Suppose a record length of 800... at half track you'd only get 68 records on a track, 2 blocks of 27200. But if you instead used 3 blocks per track then you'd get 69 records per track, 3 blocks of 18400. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html