Re: STRDSKRGZ -- MIDRANGE-L

The only messages that STRDSKRGZ and STRASPBAL normally produce go to QHST
only - I think someone posted a chunk of the manual that describes them
previously.  I did some research and used them reasonably successfully at my
previous employer, so let me summarize my understanding of what these
commands actually do.

STRDSKRGZ is a defragmenter.  Because of the scatter-loading algorithms in
OS/400 storage management, objects don't normally become fragmented on a
/400 unless there is a lot of activity on a system with nearly full drives.
However, one thing DOES become fragmented - free space.  Running STRDSKRGZ
periodically is not a bad idea simply because keeping the free space
defragged enables storage management to run slightly more efficiently.  It
should never make a noticeable difference in performance, though, unless
you've let the machine run for an extended period with very little free
space.   However, if your system is running nearly flat out very often,
every little bit helps.  Note: I ran the defrag weekly at Spartan.  It would
normally take several hours to complete, which indicated to me that it was
doing something, anyway.

STRASPBAL balances the data on the individual drive units.  Capacity
balancing just does a straight evening out of the percentage filled of the
drives, much like a scratch and reload of the system would do, and does not
require trace statistics to run.  Usage balancing and HSM balancing both
require a trace to be run first, so that the balancer knows how much each
object is used.  It attempts to load the objects across the drives so that
disk arm utilization is balanced across the units.  If you ran STRASPBAL
TYPE(*USAGE) without running one or more TRCASPBAL collections first, it
wouldn't do anything.  If your system is reasonably well balanced to start
with, it may not do anything anyway.  Note: The load source drive may not be
able to be balanced to be the same as the other units, if the stuff required
to be on that particular unit takes up more space or has more usage than
everything else.  Second note: I ran the balance weekly on that machine for
over a year, and never once did it change anything!  Of course, we had lots
of disk and never filled it to more than 75% (normally kept it below 65), so
it just didn't develop problems.

Final note: You mileage may vary, I'm not responsible if you do something
that screws up your system because of something I said or didn't say, yada
yada yada.

Dave Shaw
Simpsonville, SC

----- Original Message -----
From: "Samantha L Smith" <ssmith79@csc.com>


>
> I used this command after adding in some new disks, (not at the time aware
> of the  excellent ASPBAL commands), and it did an perfect job of balancing
> my disks.
> No messages, no indication that it had completed, nothing...
> I have since used STRASPBAL  *USAGE, and again had no indication that this
> completed successfully, or actually did anything, but performance is fine,
> and no hot disks are appearing in my reports...not that they did b4
>
> But, I'm assuming that it worked......
> Sam.
>
>
>
>
>
>
> "Leland, David" <dleland@Harter.com>@midrange.com on 13/08/2001 19:22:39
>
> Please respond to midrange-l@midrange.com
>
> Sent by:  midrange-l-admin@midrange.com
>
>
> To:   "'midrange-l@midrange.com'" <midrange-l@midrange.com>
> cc:
> Subject:  STRDSKRGZ
>
>
>
>
> Anyone used the relatively new STRDSKRGZ command? I tried this weekend and
> it doesn't seem to do anything. Doesn't give any message that it's started
> or completed, at least that I could find.
>
> Dave