Can't mount a CD/DVD

[Blake McBride]

Greetings,

I am using Minix 3.3.0.  I can mount the Minix 3.3.0 distribution CD with:

    mount -r /dev/c0d0p1 /mnt

All works fine.

But when I try any other CD or DVD with the same command I get:

mount: Can't mount /dev/c0d0p1 on /mnt: Invalid argument

I have tried several CD's and DVD's and they all fail.  I tried booting the machine from one of the DVD's and it works fine.  This means the drive can read DVD's just fine.

I also tried:

/dev/c0d0p0

/dev/c0d0p2

/dev/c0d0

Nothing works.  All the CD's and DVD's I am trying can be read by that same machine when a different OS is loaded.

Thanks.

Blake McBride

[Jean-Baptiste Boric]

I am using Minix 3.3.0.  I can mount the Minix 3.3.0 distribution CD with:

    mount -r /dev/c0d0p1 /mnt

All works fine.

It's been a while since I dealt with Minix and CD-ROMs, hopefully my knowledge in this area isn't outdated.

This command is working in this case because the Minix 3.3.0 distribution CD has a MBR partition scheme (with Minix file systems) where all the data is stored, in addition to the placeholder ISO 9660 file system.

In reality, you're mounting a MFS partition (c0d0p1) on the CD-ROM, not the ISO 9660 file system (c0d0) itself.

Also, by default Minix will try to mount as a Minix file system, to use another type of file system you need to use the -t option. However...

But when I try any other CD or DVD with the same command I get:

mount: Can't mount /dev/c0d0p1 on /mnt: Invalid argument

... the ISO 9660 file system server was disabled in Minix 3.3.0 when I found out it was thoroughly broken and beyond repair. If you need to read a CD-ROM in Minix 3.3.0, use isodir/isoread as noted in the wiki : http://wiki.minix3.org/doku.php?id=releases:3.3.0

I rewrote this file system server since and it was merged some time ago, but bad timing prevented it from shipping with Minix 3.3.0. If you check out the current development branch and build it, you should be able to mount an ISO 9660 filesystem with 'mount -t isofs /dev/c0dX /mnt'.

[Blake McBride]

Thanks, but that doesn't work either.  I did an isoread.  It copied the file without any reported errors.  The file is the right size but the MD5 is wrong.  Not surprisingly, gzip doesn't recognize it.  I didn't use the -a option.  Any ideas?

[Jean-Baptiste Boric]

It's possible that isoread may fail on corner cases, as those Minix utilities dates back from a time where it wasn't possible to mount CD-ROMs directly (and no one looked after them for ages probably).

If you can't switch to the development branch of Minix 3 (which has working ISO 9660 support), the only thing reasonable I can think of is to copy the contents of the CD-ROM on a ext2 partition and mount it instead.

[Blake McBride]

Okay, two things then.

1.  Can you report the fact that isoread does not work (or tell me how)?

2.  Can you point me in the direction on how to install the development branch?

Thanks.

Blake

[Jean-Baptiste Boric]

1.  Can you report the fact that isoread does not work (or tell me how)?

Recently a GitHub mirror was set up (https://github.com/Stichting-MINIX-Research-Foundation/minix), you can fill a issue there.
Alternatively, you can also start a new thread on this mailing list.

2.  Can you point me in the direction on how to install the development branch?

The Minix wiki has all the required documentation, this page should get you started : http://wiki.minix3.org/doku.php?id=developersguide:crosscompiling

Basically it boils down to checking out the source code using Git, and to run "./releasetools/x86_hdimage.sh" to build a hard drive image.
Alternatively, you can run "./releasetools/x86_hdimage.sh -i" to generate an installation CD.

[Blake McBride]

I did as you suggested, and I can now mount regular CD's.  Thanks!