HSFS vs ISO9660

I had always supposed that HSFS filesystems and ISO9660 file systems (both  
including the customary Rock Ridge extensions), were the same thing, but  
seemingly not so.

I have a file
-rw-rw-r-- 1 chl chl   1445068800 Oct 20  2006 sol-10-u3-companion-ga.iso
which is, of course, the Sun Companion DVD as downloaded from Sun. I can  
attach it to /dev/lofi/1 by using lofiadm, and then do
    mount -F hsfs /dev/lofi/1 /mountpoint
and it all works fine - I can see all the goodies on the Companion Disc  
without problem.

Now I have burned it onto a DVD using cdrecord on a Linux system (an NSLU2  
aka 'slug' running slugosbE as it happens). Moreover I have read it back  
using readcd, and the read-back version is bit-for-bit identical to the  
original, and can as easily be mounted via /dev/lof/* as before. So the  
burning process seems to have worked faultlessly.

BUT, when I try to mout it on the Linux system, using
    mount -t iso9660 /dev/scd0 /mnt
it fails to mount, mumbling about "wrong fs type, bad option, bad  
superblock on /dev/scd0, missing codepage or other error" (which appears  
to be the generic error message for all mount failures), and the syslog  
shows

May 22 15:19:14 (none) user.info kernel: attempt to access beyond end of  
device
May 22 15:19:14 (none) user.info kernel: sr0: rw=0, want=68, limit=4
May 22 15:19:14 (none) user.warn kernel: isofs_fill_super: bread failed,  
dev=sr0, iso_blknum=16, block=16

(sr0 is a soft link to scd0).

So How Come?
and Any Suggestions?

BTW, I also tried it as a udf file system with similar results.

Also, where can I find a list of FSTYPEs supported by Solaris; it seems to  
recognise that 'udfs' is a valid FSTYPE (whereas 'foo' and 'iso9660' are  
not), but won't mount it as such? And 'fstyp' tells me that is it 'hsfs',  
as expected.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131                       
   Web: http://www.cs.man.ac.uk/~chl
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