The 1st and most likely cause is varying amounts of data being dumped.
The 2nd most likely cause is competition for resources.
To resolve the first case, use the restore command with PARM='TYPRUN=NORUN' to
determine the contents of the various tape(s). This will produce a "simulated
restore".
e.g.
//S1 EXEC PGM=ADRDSSU,PARM='TYPRUN=NORUN
...other jcl
//SYSIN DD *
RESTORE DATASET(INCLUDE(**) -
...other parameters
/*
One additional clue I see in the provided output is varying amounts of CPU time
being used. This would, IMO, indicate varying amounts of data being dumped.
To resolve the 2nd case use RMF monitor III or OMEGAMON EPILOG(?) to view
system activity during the time periods in question.
You did not post your JCL, but it appears you are creating simultaneous disk
and tape copies of the output. The ECB wait could be tape delay, input dasd
delay or output dasd delay.
Cache hit ratios could be "wacked out" by sequential prefetch.
IOW there is no simple answer if the difference is not due to the amount of
data being dumped.
<snip>
I am trying to determine why our data set dump job (ADRDSSU) runs longer on
some days. Here is the type of dump being performed:
DUMP DATASET(INCLUDE(**) -
EXCLUDE( -
SYS1.VVDS.** -
SYS1.VTOCIX.** ) -
BY((DSCHA,EQ,YES))) -
STORGRP(PRDBAT) -
OUTDD(OUT01D,OUT01T) -
ADMIN OPTIMIZE(4) SPHERE TOL(ENQF) WAIT(0,0) Using Omegamon, I have
produced the following report. Which indicates that ECB WAIT is the primary
wait reason. I understand this is likely a voluntary wait by the program. Is
there a way to determine why these waits would be issued and why they are such
a large part of the elapsed time? Waiting on I/O to post? Shouldn't I also
see time listed for DISK ..... ACTIVE? Any input appreciated.
+-----------------------------------------------------------------------------+
| JOB = P9725451 JES NUMBER = 11741 JOB STEPS = 1 / 1 |
| JOB CLASS = B ACCT NO = INPUT QUEUE = .51 S |
| FROM 02:55 TO 04:36 ON 06/14/14 ELAP = 1:41 H PROD |
+-----------------------------------------------------------------------------+
|WAIT_REASON_____________TIME_____%_|0___1___2___3___4___5___6___7___8___9___0|
|USING CPU 4:18 M 4.2|-> . . . . . . . . . .|
|ECB WAIT 39:14 M 38.6|------------===>. . . . . . .|
|WAITING FOR CPU 27:08 M 26.7|----------> . . . . . . . .|
|JOB ELAPSED TIME 1:41 H |
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| JOB = P9725451 JES NUMBER = 18116 JOB STEPS = 1 / 1 |
| JOB CLASS = B ACCT NO = INPUT QUEUE = .81 S |
| FROM 04:35 TO 06:03 ON 06/16/14 ELAP = 1:28 H PROD |
+-----------------------------------------------------------------------------+
|WAIT_REASON_____________TIME_____%_|0___1___2___3___4___5___6___7___8___9___0|
|USING CPU 3:00 M 3.4|-> . . . . . . . . . .|
|ECB WAIT 53:09 M 60.0|------------============> . . . .|
|WAITING FOR CPU 10:42 M 12.1|----> . . . . . . . . .|
|TAPE 0803 QUE 4:29 M 5.0|--> . . . . . . . . . .|
|JOB ELAPSED TIME 1:28 H |
+-----------------------------------------------------------------------------+
+-----------------------------------------------------------------------------+
| JOB = P9725451 JES NUMBER = 04485 JOB STEPS = 1 / 1 |
| JOB CLASS = B ACCT NO = INPUT QUEUE = 1.45 S |
| FROM 04:55 TO 07:11 ON 06/17/14 ELAP = 2:16 H PROD |
+-----------------------------------------------------------------------------+
|WAIT_REASON_____________TIME_____%_|0___1___2___3___4___5___6___7___8___9___0|
|USING CPU 3:34 M 2.6|-> . . . . . . . . . .|
|ECB WAIT 1:27 H 64.1|------------============>> . . . .|
|WAITING FOR CPU 13:29 M 9.9|--->. . . . . . . . . .|
|TAPE 0801 QUE 8:55 M 6.5|--> . . . . . . . . . .|
|TAPE 0802 QUE 8:43 M 6.4|--> . . . . . . . . . .|
|JOB ELAPSED TIME 2:16 H |
+-----------------------------------------------------------------------------+
</snip>
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