SUMMARY backup tape lifetime

From: Bill Townsley (
Date: Wed Jul 24 1996 - 12:39:06 CDT

Thanks for the responses. The consensus amoung those who
responded was that 50 uses is the life of the tape. The
responses were few so I'm enclosing them in their entirety.

I called Exabyte and got a totally different answer. They
said their tapes were good for 1500 passes where a pass was
a read/write to the tape. They mentioned that a full backup
with verify is worth approximately 5 passes.

Keep in mind that these "passes" imply that you are constantly
appending to the tape from end to end. However, in practice,
you are likely to rewind to the beginning of the tape for each
new backup so your "passes" really add up at the beginning of
the tape and trail off towards the end.

BTW - Exabyte said their media had a shelf storage lifetime of
30 years.

Thanks again!

Bill Townsley

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>From Mon Jul 22 13:39:23 1996
Date: Mon, 22 Jul 1996 14:35:57 -0600
From: (Wayne McCormick)
Subject: Re: backup tape lifetime
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I've seen a lot of documentation from Legato and Epoch saying that 50 uses
is pretty much the life of the tape. But then again they may be in cahoots
with the tape manufacturers. ;-{)

Wayne McCormick Aurean Systems
Senior UNIX Analyst 2100, 444 - 5th Avenue Calgary, AB
(403) 543-2520 T2P 2T8

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>From Mon Jul 22 13:37:06 1996
Date: Mon, 22 Jul 1996 14:34:32 -0600
From: Michael Blandford <>
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To: Bill Townsley <>
Subject: Re: backup tape lifetime
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Exabyte told me that a 50 time usage was the max for reliability.


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>From Mon Jul 22 16:25:42 1996
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Date: Tue, 23 Jul 1996 09:22:59 +1000
From: (Marina Daniels)
Subject: Re: backup tape lifetime
To: (Bill Townsley)
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I tried to find out this sort of information in my previous job, it proved to be
very elusive. The best I could do was that the supplier of that particular tape
said it was guaranteed for 1 year, and when I rang up they said they thought
people would do a backup a week, so after it's been used 52 times :-)

nobody said anything definite


______________________________ Reply Separator _________________________________
Subject: backup tape lifetime
Author: (Bill Townsley) at Internet
Date: 7/22/96 12:47 PM

Sun Managers,

I have a Sun SPARCstorage Library 10 tape stacker and am using
Exabyte 8mm tapes. I'd like to find out what how frequently I
should retire my rotating tape set. That is, after how many
read/writes to the tape should I consider it to be unreliable
and replace it?

Any help is greatly appreciated,

Bill Townsley

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>From Tue Jul 23 00:20:15 1996
Date: Tue, 23 Jul 96 07:17:29 GMT
From: (Niall O Broin - Gray Wizard)
Subject: Re: backup tape lifetime
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        Please do summarise on this - it's a question I've been meaning to ask
for some time. I checked Exabyte's WWW site recently and the concept isn't even

Kindest regards,

Niall O Broin

UNIX Network Administrator, Stations and Communications Engineering Department
European Space Operations Centre
Darmstadt, Germany Ph./Fax +49 6151 90 3619/2179

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