Data DVD: Unable to mount ISO image - wrong/unknown fs type

Post by **^rooker** » Thu May 08, 2014 5:25 pm

[PROBLEM]
I have a problematic data DVD, which just won't show up when inserted.
I've used dvdisaster, to read the DVD as ISO image for further analysis.

Dvdisaster was able to read it and create the image file without any problems: Everything green

But it doesn't seem to be a proper ISO9660 format.

Running "file test.iso" just returns:

test.iso: data

although it should return something like:

test.iso: ISO 9660 CD-ROM filesystem data

[SOLUTION]
It seems that the DVD was burned on an Apple, the problem might be that the Mac-specific filesystem "HFS" was used, instead of ISO9660 or UDF.
The disk can only be read on a Mac, and (without additional wizardry) nowhere else.

There are 2 options:

1) ad-hoc:
Load the kernel modules "hfs" and "hfsplus" (HFS is the MacOS filesystem):

Code: Select all

$ modprobe hfs
$ modprobe hfsplus

2) long-term:
Add the following lines at the bottom of "/etc/modules":

hfs
hfsplus

This will load these kernel modules automatically after reboot.

Mounting it:
For some, yet unknown reason, even with the modules loaded, the DVD will not be accessible upon insert

There's also nothing showing up in dmesg. Usually, this indicates a read-problem (known from broken disks), but in this case it is very misleading.

Yet, one can rip the DVD (using dvdisaster) to an image file (e.g. "data_dvd.bin") and then mount it like this:

Code: Select all

$ mount -o loop -t hfsplus data_dvd.bin /path/to/mountpoint

That's actually a workaround.
A proper solution would be to tell whoever created the DVD to burn it so that others can also read it. I'd suggest to use ISO9660 as filesystem on that disk.

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