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Re: [Veritas-bu] Media Tape lifespan
2007-12-17 10:36:25
As a rule of thumb, if the tape gets
frozen and has 300+ mounts, I get rid of it.
Wayne BeDour
IT Unix System Administrator
PH: 313-240-3374 FAX: 313-240-3065
Internet: wbedour AT lear DOT com
From: veritas-bu-bounces AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of Jon Bousselot
Sent: Friday, December 14, 2007
11:33 AM
To: veritas-bu AT mailman.eng.auburn DOT edu
Subject: Re: [Veritas-bu] Media
Tape lifespan
I stopped using my catalog cold backup tapes when they
got over 950 mounts, not because they were failing, but because that seemed
quite high compared to other media in my system. Since I started using
the 6.0 hot catalog backup, I'm not using just two pieces of media any more, so
it has managed to spread itself out over about 8 tapes which cycle in and out
of the scratch pool like other media.
For a majority of my 3353 pieces of media, most of them are under 100 mounts
after 5 years of use. A few of them are between 100 and 300 mounts, and
when I have discovered bad media it is usually during the very first write
process. There have been occasions when restoring from a questionable
tape did not work on the first pass, but was successful on the second
pass. We keep enough backup history on tape to ensure the one bad media
is not the only copy of the file we might need.
I think netbackup increments tape mount every time a tape is inserted in a
drive and the tape header is read. If you check with the drive and media
manufacturers, they count utilization by head passes.
I'd pick a reasonable number, monitor media errors, and make the case that a
$50 tape cartridge is far cheaper than the time and effort required to recover
from bad media, and run the risk that you won't ever get it back.
-Jon
That may be about right for LTO - I'd have to check
the web but I would say you could have thousands of mounts for an LTO tape.
300+ is pretty good, and is probably the starting point for a tape to start
getting some good use.
But I am no real expert. Like I said, you could use
one tape, with horrendous problems, and end up chucking it after 10 mounts.
Alternatively, one tape could provide 5000+ mounts,
and be trouble free :-) Many companies may have tapes with double or treble
this figure!
Normally, manufactures of LTO's product a data sheet
for life span of tapes, cycles ect. May be worth looking into.
FYI I have a tape with over 700 mounts - no problems
so far.
-----Original
Message-----
From: Jackson, Todd [mailto:c-todd.jackson AT invitrogen DOT com]
Sent: Friday, December 14, 2007
3:23 PM
To: WEAVER, Simon (external); veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] Media
Tape lifespan
Yes it does help. Currently this concern
is for auditing purposes for a tape destruction plan.
Normally I would use until it dies but
here it is regulatory needs. I was thinking of setting
a lifespan between 500-1000 mounts. NB has
it set to stop using after 5000 mounts but I need
a decent number and wondering if 1000
is expecting a bit much for audits.
From: WEAVER,
Simon (external) [mailto:simon.weaver AT astrium.eads DOT net]
Sent: Friday, December 14, 2007 10:20
AM
To: Jackson, Todd; veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] Media
Tape lifespan
Well unless you get
problems, then continue to use them where possible.
As soon as I get read /
write issues, then its time to throw away....
Lifespans of tapes
(especially LTO) isnt straight forward as it may seem. I think the estimate
life is 20 - 30 years. But by then, we would be on LTO17 or something like
that!
Also, manufacturer of tape
may come into question. As a guess, if the tape is using 300+ mounts, then your
getting good serious use out of the tape.
-----Original
Message-----
From: veritas-bu-bounces AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu]
On Behalf Of Jackson, Todd
Sent: Friday, December 14, 2007
3:16 PM
To: veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] Media Tape
lifespan
How long should you use a media tape such as Quantum
LTO2 tapes?
There is no standard concerning this but I have read
a few different opinions.
I would think mounts would be more important then
writes because reading
a tape can be just a strenuous to the tape as writing
to the tape.
If anyone has something in place for tape destruction
please share
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