* radar <[EMAIL PROTECTED]> (Fri, Mar 02, 2001 at 11:32:22AM +0100)
> hi to all carbon-units out there by the way.
> (and sorry for my english)
> i dont really understand the thing with the hardware
> compression and how to handle it.
> if i understand it right, the uncompressed data goes to the tape,
> and the electronic in the tape do compress it.
Right.
> but does the tapedrive do any response to the system, at what level
> the data is compressed?
No.
> when i send 12 gig to the tape and the tape compress it down to
> 8, how do i know that there is another 4 gigs free on the tape?
You don't.
> or is it a question of trying it out?
Yes.
For typical data, you get about 1.5 compression (that is 12G compresses
down to 8, so if you have a 12G tape, you can expect to stick 18G on it)
But, this is trial and error ,
if you have only text on your disks, you can easily get 1:2 compression
(that is 24G for a 12G tape).
If you only have compressed data or random data (e.g. your entire mp3
collection) you will get no compression (or even less, using .mp3s I get
about .8 or .9 meaning that a 12G tape will only hold 10G of .mp3s if
compression is on).
> what does amanda do when it has send 12 gig to the tape (uncompressed)?
> will it stop? does it reads the tapelenght parameter? shall i manipulate
> the
> tapelenght so that amada thinks the tape is longer?
What you do is specify the tapelength to be 18G (12G times your expected
compression rate)
Currently listening to: Roger Waters-Dogs -In The Flesh (Disc 1)
Gerhard, <@jasongeo.com> == The Acoustic Motorbiker ==
--
__O If your watch is wound, wound to run, it will
=`\<, If your time is due, due to come, it will
(=)/(=) Living this life, is like trying to learn latin
in a chines firedrill
