In other words you don’t think bufno / ncp And overlapped I/O will produce anything significant
> On Mar 7, 2021, at 2:14 PM, Radoslaw Skorupka <[email protected]> wrote: > > Joseph, > > There is some nuance missing. I wrote about *significant* difference. > Actually I should say the difference is negligible. > I really don't know your application, however I guess such blocksize change > will not help you. I have suggested some other techniques to consider instead. > IMHO endusers should usually avoid using specific, rare (and bizarre) > techniques. Usually simple is better. Usually my problem was solved several > times. YMMV. As usual. > > -- > Radoslaw Skorupka > (looking for new job) > Lodz, Poland > > > > W dniu 07.03.2021 o 16:56, Joseph Reichman pisze: >> If you read a larger number of bytes into core let’s say above the bar less >> I/o should speed things up no ? >> >> >> >>>> On Mar 7, 2021, at 10:40 AM, Radoslaw Skorupka <[email protected]> >>>> wrote: >>> >>> W dniu 06.03.2021 o 16:50, Laddie Hanus pisze: >>>> LBI is available on DASD the largest block that will fit on 1 track, on >>>> the 3390 thats about 56K. Logical record (LRECL) is still limited to >>>> 32760, This is for new datasets being written. Existing datasets will read >>>> one block per i/o and will be no larger than what written. this is for >>>> BSAM read/check. manual DF/DSS Advanced services under the DEVTYPE macro >>>> will has a table of largest blocksize per decice type >>> The problem is I have never seen LBI block on DASD. >>> Can I allocate such dataset using ISPF 3.2 or JCL DD ? >>> Can I copy existing LBI dataset using IEBGENER or IDCAMS? >>> >>> It's more or less like long member names in PDSE. They exist, however I >>> haven't found any. >>> And I think it is not only my observation. >>> >>> From the other hand large blocks on tape are widely used and supported by >>> existing system tools. >>> >>> Last, but not least: author of the thread wants better performance. I would >>> not expect significant performance improvement by changing BLKSIZE =half >>> track to whole track. >>> >>> > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
