hardware: backup tape reliability

[Gary W. Swearingen]

> From: "Robert Huff" <roberthuff at rcn.com>
> To: <questions at freebsd.org>
> Sent: Friday, March 12, 2004 1:54 PM
> Subject: OT: hardware: backup tape reliability
>
>>
>> I have a friend who's trying to implement a back-up regime,
>> but running into media issues.
>> Specifically: they live in an area with extremely high
>> temperature+humidity (90-95 F/32-35 C; 90+% hum.) and climate
>> conditioning is not an option.  They need to backup critical data
>> files (code base is not an issue) and have tried floppies, ZIP
>> drives, and CDs ... all of which have proven to have a very short
>> life span.

I've no relevant experience, but I've got some hunches for your
consideration.  First, if floppies, ZIPs, and CDs can't take your
environment, then I doubt if high-density tapes will.  They should be
more reliable, but not so much so that they would work very well where
other media is rotting like meat.

Second, I suspect that those temperatures would not be a problem if
the humidity could be kept low.  AIUI, media plastic can absorb a bit
of water, causing it to expand.  If you can't manage a refrigeration-
based dehumidifier, maybe the "Dri-Z-Air"-type granules would do the
job if you keep the tape drive and tape storage confined to tight
boxes big enough to hold well-maintained granule holders.

Third, are you being careful to ensure that the tapes have had several
hours before use at the same temperature (and maybe days at the same
humidity) as they will have when used?  Changes in the media might be
the real problem.

Forth, along the same lines, at those temps, maybe your drives are
getting hot enough to cause the media to change temp too much as they
are being used.  Try putting some strong blowers on your drives to
keep them near room temp.

Again, I'm just thinking out loud, in case you haven't considered some
of that.