Post #1
0 votes
Sam
Reputation
5
Posts: 28
Joined: Jul 1, 2026, 2:30 PM
Posted: Aug 1, 2026, 11:25 AM
Allocating a file and the panel asks for RECFM, LRECL, BLKSIZE. I keep guessing FB / 80 / 0.
What do these actually control?
Thread: JCL and JCL Utilities
What do LRECL, BLKSIZE, and RECFM mean?
Started by Sam • user3 replies268 viewsLast activity 1 week ago
Post #2
0 votes
Bill
Reputation
221
Posts: 41
Joined: Aug 28, 2024, 7:08 AM
Posted: Aug 1, 2026, 1:25 PM
RECFM = record format. FB = fixed blocked (every record same length). VB = variable.
LRECL = length of one record in bytes. 80 is classic card image.
BLKSIZE = how many bytes per block on disk. Often a multiple of LRECL for FB. 0 can mean "let the system pick" in some shops.
Wrong LRECL vs what the program writes = pain later.
Post #3
1 votes
Susan
Reputation
167
Posts: 26
Joined: Jan 19, 2025, 4:12 PM
Posted: Aug 2, 2026, 12:25 PM
If you are cloning an existing file, copy its attributes instead of inventing new ones.
You must be signed in to reply to this thread