Jim, The LOG dataset can stay 3120 because most of the entries would not fill a block. It is the OUTPUT DCB that needs to have BLKSIZE=0
Regards, John K Jim Mulder from the IBM Mainframe Discussion List <[email protected]> wrote on 07/26/2013 12:45:34 AM: > From: Jim Mulder <[email protected]> > To: [email protected] > Date: 07/26/2013 09:15 AM > Subject: Re: BLKSIZE=3120 > Sent by: IBM Mainframe Discussion List <[email protected]> > > >> > A customer (mildly) complained thatsome of our product allocations still > use > BLKSIZE=3120. I vaguely remember trying to change all of them to > BLKSIZE=0 many years ago (probably before OS/390) and running into some > issues with certain IBM utilities. Unfortunately, I can't remember the > specifics. > > In starting to revisit this again, I noticed numerousoccurrences of '3120' > > in IBM help and documentation. For example, the TSO/E RECEIVE command HELP > > claims that the log data set must be BLKSIZE=3120: > > <TSO/E RECEIVE command HELP> > LOGDATASET You may specify an alternate data set to be > used for the logging of the transmitted data. > This data set will be created if it does not > exist. The data set should be created with > a logical record length of 255, a record format > of VB and a blocksize of 3120. > ... > > LOGDSNAME You may specify an alternate data set to be > used for the logging of the transmitted data. > This data set will be created if it does not > exist. The data set should be created with > a logical record length of 255, a record format > of VB and a blocksize of 3120. > </TSO/E RECEIVE command HELP> > > Is this just outdated help? Or does this restriction still exist? > >> > > I looked at the current TRANSMIT/RECEIVE code, and it still > specifies BLKSIZE=3120 when it creates a LOG data set, and still > hardcodes BLKSIZE=3120 on its DCB for the log data set. I engaged > in battle with the former TSO developers a long time ago (maybe over > 20 years ago, maybe even before the advent of System Determined > Blocksize). I wanted them to at least remove the BLKSIZE=3120 > on the DCB so that if someone (like me) was sensible enough > to allocate his own log dataset with an efficient BLKSIZE, > TRANSMIT/RECEIVE would cease to override that on the DCB and thus > no longer change the BLKSIZE to 3120. Since the stupid DCB > specification is still there, exists, I apparently lost that battle. > > Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
