Dear all,

I'm having an interesting experience mounting a particular CD-ROM.

It's the official Maple 9.5 CD but reburnt by our University under
licence, and contains different file systems for Windows, Linux, and Mac,
such that when you pop it in a Windows system it *only* sees is the
Windows tree, etc.  I've not needed to pay much attention to how it works
until now, when I popped it into a SL 4.1 machine for the first time and
it mounted up the Mac tree which is an hfs file system, rather than the
Linux tree on an iso9660 fs.

# uname -a
Linux pc006007.shef.ac.uk 2.6.9-11.EL #1 Thu Jun 9 15:23:29 CDT 2005 i686 
i686 i386 GNU/Linux

[root@pc006007 ~]# mount /media/cdrecorder/
mount: block device /dev/hdc is write-protected, mounting read-only

[root@pc006007 ~]# more /etc/mtab
<snippage of other mounts>
/dev/hdc /media/cdrecorder hfs ro,nosuid,nodev 0 0

-------------------------------------------------------------

(On SL 3.0.5 it works as expected:

[root@acml27 ~]# uname -a
Linux acml27.shef.ac.uk 2.4.21-37.EL #1 Wed Sep 28 12:31:02 CDT 2005 i686 
i686 i386 GNU/Linux

[root@acml27 ~]# mount /mnt/cdrom/

[root@acml27 ~]# more /etc/mtab
<snippage of other mounts>
/dev/cdrom /mnt/cdrom iso9660 ro,nosuid,nodev 0 0

-----------------------------------------------------------------

Now, back to SL41, I can mount it specifying the fs explicitly:

[root@pc006007 ~]# mount -t iso9660 /dev/hdc /media/cdrecorder

and all is fine, I get the Linux tree.

My question is, whereabouts is the file system detection going wrong?  
It's not majorly important, since I can mount it manually, but I'm
curious.  My limited understanding is that mount (when the fs is
unspecified) looks at the superblock; if this fails, it will attempt to
mount the device using all of the fs specified in /etc/filesystems, and in
my case iso9660 comes before hfs. So, assuming it tries them in order, I
would expect the iso9660 fs to be mounted by preference. Which suggests
that it hasn't got this far, and is in fact reading from the superblock?  
But why is SL3.0.5 getting it right? 

I've tried this with two Maple CDs, so I'm assuming it's not a bad CD
(although it could be a bad batch, I guess...)

Thanks in advance (and thanks to all the SL team and contributors, from a 
satisfied user & lurker),
Richard.

-- 
 Dr. Richard Balthazor         
 Scientific Officer:    Space Physics and Upper Atmosphere Research Group 
 Tel: (+44)(0)114 222 3711              Department of Applied Mathematics
 Fax: (+44)(0)114 222 3739                        University of Sheffield
 Email: [log in to unmask]      Sheffield S3 7RH, United Kingdom