You should up your buffers (and NCP). Two will be spending a lot of time waiting.
Just remember that after a CHECK shows EOF, you should not expect a valid status from the pending reads. On Fri, 28 Nov 2014 12:20:08 -0500 Sam Golob <sbgo...@cbttape.org> wrote: :>Hi Folks, :> :> I was just involved in an exercise to improve an old file copying :>program from CBT Tape File 316. It is called FFYCOPY, and it was :>written in the mid-1970's by Frank Yates (courtesy of Jim Marshall). :>This program's "copy engine" uses BSAM with double buffers, and for its :>time, it was very fast, since BSAM (using the READ and WRITE macros) :>deals with copying blocks of data instead of records. Of course, QSAM :>(using the GET and PUT macros) is geared to copying records. :> :> Most sequential file copying programs use QSAM, because the :>granularity is at the "record" level and not at the "block" level. But :>if speed is a priority, BSAM, copying equal sized blocks to equal sized :>blocks, can be an advantage. :> :> I'm not telling anybody here to give up the copying programs they :>have been using (there are many of them out there), but this is for the :>purpose of discussion, and I hope it helps somebody in the process :>(maybe even me). :> :> FFYCOPY, being a very simply written program (except for the skill :>in writing the engine), needs to have the output dataset having :>identical RECFM, LRECL, and BLKSIZE to those of the input dataset. To :>guarantee that, it simply overlays those attibutes in the output dataset :>before OPENing it. This may get into problems if you're copying a :>sequential dataset to a member of a pds. The copy does not reblock the :>dataset (as it uses BSAM very simply), and the output pds can be messed :>up. To avoid such problems, I put safeguards into FFYCOPY (see FFYCOPY :>in File 316 on the Updates page of www.cbttape.org), so that if RECFM, :>LRECL, or BLKSIZE don't match, the copy is not done. I also added a :>SYSPRINT dataset to report status of what happened. And to force the :>overlay of the attributes in the output dataset (as in the old version), :>you can code PARM=O in the EXEC statement. :> :> I'd be interested in hearing if there are any issues nowadays in :>copying BIG files FAST. Of course the world has progressed a lot in 40 :>years (snicker), but I'd still like to hear some thoughts on the subject. :> :> Thanks much. All the best of everything to all of you. :> :>Sincerely, Sam :> :>---------------------------------------------------------------------- :>For IBM-MAIN subscribe / signoff / archive access instructions, :>send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN -- Binyamin Dissen <bdis...@dissensoftware.com> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
