On Friday 29 November 2002 09:54, Joachim Scharfenbaum wrote:
>Hello,
>
>I want to use SDLT220 to backup my files. Has anyone got the
> tapetypes for a Quantum SDLT220?
>
I don't, but there is a tapetype program in the tape-src dir that 
isn't built by default, you cd to the dir and 'make tapetype'.

To get correct answers from it, you must make sure that any 
compression the drive can do is turned off before starting 
tapetype, which will take quite a while to run, else it will report 
the tape as smaller than it should be because the compressor in the 
drive will be overpowerd by the data from /dev/urandom, which is 
the data source for tapetype as it runs.  This will tend to give 
falsely small working capacities of the tape, sometimes by 15 to 20 
percent too small.  Besides, software compression by amanda can 
often smunch data down to <20% of its original size if the email 
reports I get from amanda are any indication.  So find the 
dipswitch and shut it off for good is the general recomendation on 
this list.  Amanda will, once some history is built up, knows 
pretty well how much a given disklist entry will compress, and can 
therefore make some pretty accurate guesses as to how much data she 
can shove down the cable before the tape will hit EOT.

-- 
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz  512M
99.19% setiathome rank, not too shabby for a WV hillbilly