Re: Temporary tape errors

[Jeff Crosby <jlcrosby@xxxxxxxxxxxxxxxx>]

Our HW service provider did some testing today on a similar System i 520 in
their data center.  Same internal tape drive as us.

A Save21 for them generated over 9,000 temporary tape write errors.  This
compares to 6,160 temporary write errors we got Wednesday morning and
42,051 temporary write errors we got yesterday (Thursday) morning.

They called me to report this thinking (I think) that temporary errors are
par for the course, Not A Big Deal, and therefore I shouldn't be worried
about it too much.  OK, a few errors I can buy, but 9,000?  42,051?  That
seems awfully excessive to me no matter how "serious" a temporary error is
supposed to be.

The tech that called me is going to another customer with a similar system,
only with an 8mm internal drive, and see what kind of errors they are
getting.

In the meantime, for this mornings backup, we used the 3580 library for a
full, complete system save and got 0 temporary write errors.  That tape was
then dupped to 2 other physical tapes (on another 3580) and a virtual tape
with 0 temporary /read/ errors.  Those 2 tapes that we dupped to (3580 to
3580) also show 0 temporary write errors.

So temporary read and/or write errors evidently can be avoided.  I'm not
convinced that I should accept them at the level we're receiving them.
 What's everybody else's experience before/after a large save?




On Mon, Feb 24, 2014 at 10:36 AM, <rob@xxxxxxxxx> wrote:

> Jeff,
>
> Occasionally someone on the list will say that if you are getting
> temporary write errors on a tape you should discard the tape.  I tend to
> hold on to the tape for awhile and check on stuff.  Granted, we're a
> little different.  We have multiple drives in the one library and the same
> drive may not get hit daily.  But there are ways to see which drive was
> used.  What we've noticed is that it's almost always the drive.  We get
> the drive repaired and the errors go away.  We then initialize those tapes
> with a clear(*yes) just to be doubly sure.
> I think we've 'retired' one tape from wear.
>
>
>
> Rob Berendt
> --
> IBM Certified System Administrator - IBM i 6.1
> Group Dekko
> Dept 1600
> Mail to:  2505 Dekko Drive
>           Garrett, IN 46738
> Ship to:  Dock 108
>           6928N 400E
>           Kendallville, IN 46755
> http://www.dekko.com
>
>
>
>
>
> From:   Jeff Crosby <jlcrosby@xxxxxxxxxxxxxxxx>
> To:     Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
> Date:   02/24/2014 10:11 AM
> Subject:        Temporary tape errors
> Sent by:        midrange-l-bounces@xxxxxxxxxxxx
>
>
>
> All,
>
> I decided it was time to replace some of our backup tapes (LTO2).  The
> PRTERRLOG didn't have the > or >> on any volume, but I thought the
> temporary read errors were high and it has been several years.
>
> I deleted the lifetime stats on the ones to be replaced.  I did an INZTAP
> one tape and then did a DSPTAP on it.  The stats on that tape, which were
> nonexistent because I had deleted them, showed 16 temporary write errors,
> no read errors.  And all I did was INZTAP followed by DSPTAP on a brand
> new
> tape that I removed from the cellophane.
>
> So I did an INZTAP on another brand new tape, then a PRTERRLOG on it.
>  Shows 10 temporary write errors, no read errors.  Did a DSPTAP on it.
>  Still shows 10 temporary write errors (since a DSPTAP is a read, duh) and
> no read errors.
>
> What is this telling me?  My tape drive has an issue?  It's an internal
> 5755 installed 2-3 months ago.  It has been cleaned with a cleaning
> cartridge twice.
>
> Thanks.
>
> --
> Jeff Crosby
> VP Information Systems
> UniPro FoodService/Dilgard
> P.O. Box 13369
> Ft. Wayne, IN 46868-3369
> 260-422-7531
> www.dilgardfoods.com
>
> The opinions expressed are my own and not necessarily the opinion of my
> company.  Unless I say so.
> --
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