OS Simulation › DMSTVI Exit › Examples of Interactive OS Simulation Using SYSPARM › Increasing Performance by Increasing Input and Output File Blocksize

Increasing Performance by Increasing Input and Output File Blocksize

You can greatly increase the performance of your programs that read and write tapes if you specify a larger blocksize for the input and output files. When you use a larger blocksize, fewer I/O requests are necessary, and it is possible to write more information to each tape.

This EXEC specifies a blocksize of 4000 for the input and output files.

'FILEDEF INMOVE DISK FIRST FILE A ( RECFM FB LRECL 80 BLKSIZE  4000  '
queue 'RETPD 100'
'FILEDEF OUTMOVE TAP1 SL 1 ( RECFM FB LRECL 80 BLKSIZE  4000  SYSPARM (?)'
queue  'FIRST.DATA.SET'
'LABELDEF OUTMOVE FID ? VOLID SCRATCH FSEQ 1'
'MOVEFILE INMOVE OUTMOVE'
exit RC