File Utility Program (FUP) Management Programming Manual

FUP Commands and Responses
File Utility Program (FUP) Management Programming Manual—523322-001
3-6
CHECKSUM Command
Considerations
•
CHECKSUM reads each block of data from each file specified by ZFUP-TKN-FILE
and recomputes the checksum value for each block. However, CHECKSUM
rewrites only the blocks with incorrect checksum values.
•
Checksum errors usually indicate a potential data integrity problem. CHECKSUM
recomputes the checksum value for blocks of data but does not correct any data
that might have changed.
•
CHECKSUM aborts if either of these occurs:
°
On a G-series system, the Subsystem Control Facility (SCF) Storage
Subsystem STOP DISK or STOPOPENS DISK command was executed for the
disk volume specified by ZFUP-TKN-FILE
°
On a D-series system, a Peripheral Utility Program (PUP) DOWN or
STOPOPENS command was executed for the disk volume specified by
ZFUP-TKN-FILE
Example
Figure 3-1 shows a TAL example of a high-level integer procedure for the CHECKSUM
command: