Charles, This is why in my earlier post I said that 16 works for half track blocking. 8x27998=223984 which means the chain length will be limited to 8 half track blocks. However MVS loves CPU/IO overlap, so we have another eight buffers that can be processed while the other eight are used for IO.
I like Barry's formula, because it is not arbitrary - it is based on the limits of SAM-E. However I would recommend doubling his result. Ron > > "Experiments with BUFNO for Sequential Access (BSAM,QSAM), including > that rare experiment of RTFM (Reading The Fine Manual), discovered that > unstriped SAM is limited to transfer of 240K bytes per I/O, and is also > limited to a maximum of 30 buffers." > ---------------------------------------------------------------------- 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
