Paul:

I think the key phrase was "we do append". I'm guessing that the tape
transit time to search for the next available sequence number is largely
the difference. I'd try to put an exit in the daily control group with a
"starting now" and "ending now" just before/after the *ALLUSR. Then
compare that time to the weekly. Assuming they are about the same, then
the difference is seek time on the tape. LTO seek time is abysmal, so it
would not surprise me to find this out.

On Thu, Aug 27, 2015 at 9:46 AM, Steinmetz, Paul <PSteinmetz@xxxxxxxxxx>
wrote:

On our Production LPAR, every night at 22:00, I run a full BRMS save SWA.

Cause . . . . . : Command to execute is: STRBKUBRM CTLGRP(SAVFULL05)
SBMJOB(*NO) APPEND(*YES) ACTIVITY(*CTLGRPATR) RETENTION(*DAYS 45).

BRM16A1 Diagnostic 40 08/27/15 00:22:55.539417
Q1AC0SLIB QBRM *STMT Q1ARBK QBRM *STMT
Message . . . . : Backup *ALLUSR, type *FULL completed with errors.
for sequence 57372,

Once a week, same time, we run a different job using the same control
group with different retention overrides and move policies.

Cause . . . . . : Command to execute is: STRBKUBRM CTLGRP(SAVFULL05)
SBMJOB(*NO) APPEND(*YES) ACTIVITY(*CTLGRPATR) RETENTION(*DAYS 396)
MOVPCY(CYCBRC396).

BRM16A1 Diagnostic 40 08/25/15 00:10:34.356003
Q1AC0SLIB QBRM *STMT Q1ARBK QBRM *STMT
Message . . . . : Backup *ALLUSR, type *FULL completed with errors.
sequence 18100

The once a week *ALLUSR part of the save is consistently 10 to 15 minutes
faster than the daily save.
During the backup window, no batch jobs, only a handful of interactive
users.

Why would a retention override result in a performance improvement during
the *ALLUSR?
*ALLDLO and *LINK times are the same.
We do append, sequence numbers are higher for the nightly save compared to
the weekly save.

Thank You
_____
Paul Steinmetz
IBM i Systems Administrator

Pencor Services, Inc.
462 Delaware Ave
Palmerton Pa 18071

610-826-9117 work
610-826-9188 fax
610-349-0913 cell
610-377-6012 home

psteinmetz@xxxxxxxxxx
http://www.pencor.com/






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