new Ubuntu user w/ questions

[Bob Holtzman]

On Thu, 7 Feb 2008, Rashkae wrote:

> Bob Holtzman wrote:
> > I recently decided to try out Ubuntu and have a couple of questions. I have RT'd a couple of FMs
> > and tried to wade thru this list's archives with no luck. I'm running Ubuntu 7.10.
> > 
> > 1. What is the purpose of having both /media/cdrom and /media/cdrom0? I realize one is a link 
> >    to the other but I'm wondering why both exist. The same applies to /media/floppy and 
> >    /media/floppy0.
> 
> Backwards compatability and improvements.  /media/cdrom(n) can exist for 
> as many cd-rom devices as you care to cram on a single system, but 
> /media/cdrom (which lots of people/programs expect as the default) can 
> only point to one.
> 
> >    
> > 2. When trying to add content to a rewritable DVD that has previously been written to I get the 
> >    warning that I don't have permission to write to that directory. When I try to chmod 777(as
> >    root)/media/cdrom0 I'm told it is a read only directory even tho /etc/mtab shows it mounted as rw. 
> >    What am I missing?
> > 
> 
> RW CD's and DVD's aren't really RW (huh, please, bear with me).  The 
> ISO9660 file system used by default only works as a complete image, and 
> does not allow for random write access (data is recorded in a continuous 
> spiral track, not divided into sectors / blocks like a traditional hard 
> drive.  There is a standard that exists to mount a RW optical device 
> with random read write access, (if your drive supports it properly. Last 
> I investigated this, most did not) but it's very rarely used.  I'm not 
> sure what the status of this is in Linux or what packages you would need 
> to get it working.  In general, think of RW Optical media as something 
> you can erase and and start over.  (You can, of course, append a write 
> session to add files.  Use your favorite DVD burning software.  You 
> can't write directly to the mounted file system, however)

Thanks for the information. Is the /media/cdrom->/media/cdrom0 unique to 
Ubuntu or is this the common setup now? I've been running Redhat 7.3 ever 
since it was released and haven't kept up with developements.

One more question: why a /media in addition to the /mnt I am used to? 

-- 
Bob Holtzman
"If you think you're getting free lunch,
 ......check the price of the beer!"