Subject: Re: CD-R, CD-RW, Travan tape-drives...
To: Richard Rauch <rauch@eecs.ukans.edu>
From: None <seebs@plethora.net>
List: netbsd-help
Date: 12/26/1998 14:34:56
In message <Pine.LNX.3.96.981226135646.13321B-100000@pink3>, Richard Rauch writ
es:
>Hm.  Okay, I'll take your word for it, but I don't understand.  Where
>would I look if I had the time to read/understand the difference?  Or can
>you give me a technical explanation off-hand?  (I.e., the question is "Why
>do CD-RW drives not support rewriting in the same manner as a hard disk?"

Because really they're CD-R's that happen to support wiping out the old data
and writing again.  It's like the old flash memory used to be - you can write
until it's full, then you can start over.  Mostly.  Think of it as more like
tape media than like disk media, but with random access to data already
written.

>I am vaguely aware that CD-RW sectors start to go bad after a thousand or
>so rewrites, so you need to "scatter" the usage pattern around the disk to
>get a long life out of the media.  Is that the only problem?  In and of
>itself, that would make it seem "unwise" to install a standard filesystem
>on a CD-RW, but not unworkable.) 

I've been told that people start seeing problems within 20 writes or less...

>...but one would have to have BSD/OS to get one's hands on this, yes?  Or
>is the CD-RW support seperate & freely-available?

I don't know, but there's also Linux support, which would be harder to port,
but it's around.

-s