ADSM-L

Re: When is a tape too old

2002-12-19 00:11:25
Subject: Re: When is a tape too old
From: "Prather, Wanda" <Wanda.Prather AT JHUAPL DOT EDU>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Wed, 18 Dec 2002 16:51:20 -0500
If you want to track the number of mounts TSM does to your tapes that's
pretty easy, you can get it from the SUMMARY table.

Set up a query, for example :

select date(start_time) , drive_name, volume_name from summary where
activity='TAPE MOUNT'

You can use perl (from Windoze or *IX) or a shell script from AIX to drive
that query and send the output to a file.
If you use the -commadelimited parm, you will get a comma-delimited file
that looks like:

header garbage
2002-12-dd, xxxmt1, VVVVVV
trailer garbage


You can have the script strip off the headers and trailers and append the
data to the previous run to build a running log.  I add some parms to the
query to limit the date/time range to the past 24 hours, then run the script
daily via cron (NT scheduler to you Windows types).

So in effect, I"m creating an accounting log just for tape mounts.  Since
the output is comma-delimited, it's pretty easy to read the file with most
anything -- SAS, perl, rexx, or even EXCEL if you don't let the file get too
big -- and tally up your mount counts.

That being said, I'm not sure how useful mount counts are in determining
tape life.  (I started doing this to track the mount load on my DRIVES, not
the volumes specifically).  I've never heard of a mount limit that
determines the  lifespan of a 3590.  (Since we do vaulting, I expect to have
my tapes damaged by mishandling long before they get a chance to wear out
from mounting :>)

On the other hand, it would be real nice to keep a data base like this, so
if you start seeing I/O errors over time, you might have some useful data.

************************************************************************
Wanda Prather
The Johns Hopkins Applied Physics Lab
443-778-8769
wanda_prather AT jhuapl DOT edu

"Intelligence has much less practical application than you'd think" -
Scott Adams/Dilbert
************************************************************************






-----Original Message-----
From: Diana Noble [mailto:djk AT UMICH DOT EDU]
Sent: Tuesday, December 17, 2002 10:25 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: When is a tape too old


We use 3590 J's and K's.  I've been asked what the lifespan of these tapes
are.  I've seen where the shelf life might be 10-12 years, but have not been
able to find anything about the regular use of them.  Our tapes are returned
to
scratch when they become empty, so they are not private tapes.  It's my
undertanding that we lose the number of mounts for the tape when it is moved
from scratch into a private storage pool.  Is there a way to track it's
usage
and and know when it's reaching it's maximum lifespan?  Is there an
approximate
lifespan for these tapes when used regularly?  Or do I just wait until IO
errors start occurring and remove it then?

Thanks,

Diana

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