Elardus,
I found this jcl which is currently being run to reorg. the MCDS in an LPAR. It
has the DCB specified:
/* //STEPA EXEC
PGM=IEFBR14,COND=(0,NE) //MCDS DD
DSNAME=SYS2.MBMCDS.T,DISP=(,CATLG), //
DCB=(RECFM=VBS,LRECL=2044,BLKSIZE=0), // SPACE=(CYL,(550,550))
/* The file is
reorged using EXPORT/IMPORT. It is not recreated.
This is what the DEFINE CLUSTER looks like/*
//DEFINE EXEC PGM=IDCAMS,TIME=1439
//SYSPRINT DD SYSOUT=* //HSMMCDS DD
UNIT=3390,VOL=SER=PROD03,DISP=SHR //SYSIN DD *
DEFINE CLUSTER -
(NAME(SYSP.MCDS.PROD) VOLUME(PROD03) - CYLINDER(2500 0)
FILE(HSMMCDS) - RECORDSIZE(435 2040) FREESPACE(0 0) -
SPEED BUFFERSPACE(530432) - INDEXED
KEYS(44 0) SHAREOPTIONS(3 3) - UNIQUE NOWRITECHECK) -
DATA (NAME(SYSP.MCDS.NEW.DATA) CISZ(12288) ) - INDEX
(NAME(SYSP.MCDS.NEW.INDEX) CISZ(2048) ) /*
//
From: Elardus Engelbrecht <elardus.engelbre...@sita.co.za>
To: IBM-MAIN@LISTSERV.UA.EDU
Sent: Thursday, February 9, 2017 11:32 AM
Subject: Re: DCB NECESSSARY?
Paul Gilmartin wrote:
>>To Esmie, I see there are NO LRECL and BLKSIZE in this snippet. Seemed you
>>can just let IDCAMS figure it out for you.
>Oooh! This is tricky. Some utilities "figure it out for you", others don't,
>yet others will override whatever you code, sometimes corrupting an existing
>non-empty PDS.
Indeed. This is tricky just as you said. The Big Blue a$$umed you are using SMS
with the correct SMS constructs.
In that snippet, if the IMPORT does not work after the EXPORT, then whoever is
using it, is really SOL.
I initially recommended using IDCAMS to define the backups, then shut every HSM
down, REPRO, ALTER both sets and start all again. I safely used that method
without problems at all (and without being called before management!!! ;-D )
Perhaps someone could tell what is the correct LRECL and BLKSIZE after all the
EXPORT/IMPORT work is completed successfully.
>And the prevailing recommendation is omit BLKSIZE; let SDB operate.
Yup. Let SDB decides depending on whatever device you have.
Unless you're sitting with IBM's default compiling procs like IGYWCLG (Compile,
Link, Go), then you had to insert these
DCB=(RECFM=U,LRECL=0,BLKSIZE=6144) or BLKSIZE=<your favourite value>
in //SYSLMOD DD DSNAME=&&GOSET(&GOPGM), etc ...
... to avoid LKED with RC=12 because SMS has the last say. This is WAD and I'm
not complaining about this.
>But are there still facilities that require an absurd BLKSIZE, such as <=3120?
I think I have seen some of them in the ancient past. With the small disks
then, it was a cruel wastage of space.
>... If DCB=(...) is optional for tape, DASD, (terminal, punch, reader,
>printer, spool, ...), why not likewise for PATH?
Good question. PMR time for the device definition tables [which fill in the
rest if not coded in JCL or overridden by SMS]?
Groete / Greetings
Elardus Engelbrecht
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