On Tue, 23 Mar 2021 16:54:57 +0100, Radoslaw Skorupka wrote: > >>> However when you specify records or kilobytes, the system assumes the >>> following: >>> a) you have only inkling about mainframe DASD >>> >> Wrong! It forces me to know more than I care to. > >Agreed. However that was the intention. Personally I discourage students >from using AVGREC. It is counterintuitive IMHO, especially when you have >to record sizes - in LRECL and SPACE. >Of course TRK/CYL require some calculation to know how many records... - >it is the same like in KB or MB. > That hypothetical naive programmer shouldn't know TRK/CYL. They're no longer real anyway.
>>> b) you want such and such number or kilobytes, megabytes or records. AT >>> LEAST. >>> Suppose I specify RECFM=VBS,LRECL=X,BLKSIZE=0. What should I say in SPACE, etc. to get 1GB. Without relying on device specifics. >> A PITA when I'm generating JCL with a program. Why does IBM choose >> to afflict me with 20th Century, 2311 mentality? > >Agreed. I would vote for SPACE=(GB,(10,5)) and TB, and MB, and PB of >course. > From the other hand I'm so used to TRK and CYL so I don't feel any pain >with that. Especially I saw the last non-3390 DASD in... > Don't think of the 3390 geometry as divinely ordained. A recurrent legend here is that IBM once considered FBA, but deemed the software support cost prohibitive. So real FBA emulates CKD. Some decades ago I attended a presentation where IBM touted an online service. The default subscription included 1 MB (sic) DASD storage. Question from the audience: "How many cylinders is that?" I forget the answer. It should have been, "It depends ..." -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
