Hello Mark and other,
This is an interesting topic,
In the past I had thinking that our dlt tape carts would last about 200-300
mounts before getting into trouble. Most tapes did not do this, but the pool
of tapes used for netbackup catalog tapes would reach these numbers without
too much trouble. We also saw this with tapes used for rman archive log
backups when the dba's had the archive logs set to small quick jobs.
Of course it is always hard to determine if a problem is with the tape cart,
tape drive, software(includes driver) or all three. After all if a tape
drive is bad, it is not a good source for knowing if a tape is bad or not.
With the lto-2 tape carts, someone on this list posted a ref to a fuji tape
site which listed many 1000's of mounts. So it would seem that if they are
correct, it would almost never be the tape.
And our tape library ce would almost always think that it was the tape and
not the drives.
Has anyone know of tools (unix or windows) other then tcopy that is useful
for testing tapes?
Something like the fdr product for the ex-mvs folks out there. Or the
tapemap program for ex-vm users. Or Mozart/Qtip for the ex-Sperry Univac
folks.
How about a tool for dumping the error data from tape drive?
Even so, it does seem that tapes are getting better.
----- Original Message -----
From: "Mark Pinder" <[EMAIL PROTECTED]>
To: <veritas-bu@mailman.eng.auburn.edu>
Sent: Tuesday, November 01, 2005 2:49 PM
Subject: [Veritas-bu] RE: Number of mounts before getting rid of a tape?
Tape life is measured differently for different Drive/media vendors. Most
of them have Numbers that appear to be inordinately high based on actual
failure rates.
Sony says that AIT tapes are good for 10,000 loads and/or 30,000 end to
end passes. I've never seen one actually last this long, but I've also
never seen them used this much either.
LTO-2/3 media also has an anticipated life of several thousand loads and
many more end to end passes.
As a HW vendor for this stuff, I have to say that I personally think these
are simply Marketing numbers invented through ideal testing (Like MPG for
cars) and I would not trust them.
At the same time, we have customers who have been using the same media for
over 3 years without ill effect.
The best advice I can give you about it is to use it until it fails, but
anticipate that failure and have some amount of new media (~5%) brought in
every quarter or so. This will give you a surplus stock to replace tapes
that die and give you the opportunity to remove some of the most used
tapes. These can be "filed" somewhere and used in case of emergency.
I hope this helps.
Mark Pinder
Systems Engineer
Spectra Logic
www.spectralogic.com
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