Mounting ULTRIX CDROMs on Linux

[Malte Dehling]

On Thu, May 20, 2021 at 04:11:18PM -0400, John-Paul Stewart via cctalk wrote:
> On 2021-05-20 4:01 p.m., Warner Losh via cctalk wrote:
> > On Thu, May 20, 2021 at 1:56 PM Antonio Carlini via cctalk <
> > cctalk at classiccmp.org> wrote:
> > 
> >> I'm running Linux Mint (an ubuntu derivative) and I want to mount ULTRIX
> >> CDROM discs to see what I can see.
> >>
> >> (I'm eventually going to image these, but I presume that will "just
> >> work" with dd or ddrescue).
> >>
> >> They are supposed to be UFS format (according to the net) and that
> >> usually means you have to tell mount exactly which option to use (as not
> >> all UFS implementations are compatible).
> >>
> >> I've tried (all the options I can find) and failed:
> >>
> >> $ sudo mount -t ufs  -o ufstype=44bsd /dev/sr1 /tmp/mount
> > 
> > 44bsd is likely too new. ufstype=old or =sunos or =sun might work.
> 
> Setting ufstype=sun will indeed work for loopback mounting Ultrix CD images.
> 
> With physical CDs, the Linux CD-ROM driver expects the filesystem to use
> 2048 byte blocks but the UFS CDs have 512 byte blocks.  So you'll also
> have to add "loop" to the options:
> 
> sudo mount -t ufs -o ro,ufstype=sun,loop /dev/sr1 /tmp/mount
> 
> That will mount the physical CD using a loopback device so you can
> access the 512 byte per block filesystem.  (FWIW, I learned that trick
> with IRIX EFS CDs, which have the same problem.)

Wow!

I never expected to learn something new about mounting CDs tonight :-)

Thanks!


-- 
Malte Dehling
<mdehling at gmail.com>