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Re: Tape compression fiasco

On Sun 22 Jul 2001, Luiz Emediato wrote:
> Companies say that if you have compressed files they won't be compressed 
> again. This is obvious, but what about the tape density.
> As far as I know, compression would mean high density on tape.

Your assumption is wrong.
The density gives you 4GB, the compression doubles that to 8GB
(marketing speak, not my opinion!). To get more on a tape, you need
higher density, not higher compression. Two different things.

> It seems that the limit of 8GB stated by companies is a fiasco !

Well, er, DUH! :-) Same problem with 1GB = 1000"MB" = 1,000,000,000
bytes, not 1024 x 1024 x 1024 = 1,073,741,824 which means that the
GB used by marketing is more than 7% less than what a technical person
would expect.

> Has anyone backup more than 4GB of data on DDS-2 tapes successfully ?

Backup executables, text, data, ... anything that's not already
compressed (i.e. not mp3, jpg, gif, ...)

Paul Slootman
home:       wurtel@spamcop.net   http://www.wurtel.demon.nl/
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