Determine type of CD format?

[Markus Robert Kessler]

Hi everyone!

Well, sounds somehow strange, but:

I have received a CD filled with cardiac CT images. The disc seems to be
around 1/3 full, so, assuming 200-250MB of data.

Unfortunately, the physicians used a filesystem (joliet or something
else) that I cannot mount. Even copying /dev/sr0 to file does not work.
The CD drive tries to read, stops, tries to read, stops. Over and over.

B.t.w., I have no windows machine to test with.

Anyone have an idea, how to check, what filesystem this is?

Thanks!

Best regards,

Markus

[David W. Hodgins]

Post by Markus Robert Kessler
Hi everyone!
I have received a CD filled with cardiac CT images. The disc seems to be
around 1/3 full, so, assuming 200-250MB of data.
Unfortunately, the physicians used a filesystem (joliet or something
else) that I cannot mount. Even copying /dev/sr0 to file does not work.
The CD drive tries to read, stops, tries to read, stops. Over and over.
B.t.w., I have no windows machine to test with.
Anyone have an idea, how to check, what filesystem this is?

It's a Microsoft extension to iso9660.
http://www.faqs.org/docs/Linux-HOWTO/CDROM-HOWTO.html#AEN1328

There's also Rock Ridge ...
https://wiki.osdev.org/ISO_9660#Rock_Ridge_and_Joliet

Make sure your kernel is configured to support it ...
# zgrep CONFIG_JOLIET /proc/config.gz
CONFIG_JOLIET=y

To create a cd with Rock Ridge...
# rpm -q -i xorriso|grep ^Sum
Summary : ISO 9660 Rock Ridge Filesystem Manipulator

# grep -e iso -e fat /etc/filesystems
exfat
iso9660
vfat

I got tired of replacing cd/dvd drives that stop working due to me being a
heavy smoker. Haven't used one in years, so don't remember all of the details
needed to work with them.

If I remember correctly, it must be mounted using vfat.

Regards, Dave Hodgins

[Markus Robert Kessler]

On Thu, 10 Aug 2023 11:50:12 -0400, Markus Robert Kessler

Post by Markus Robert Kessler
Hi everyone!
I have received a CD filled with cardiac CT images. The disc seems to
be around 1/3 full, so, assuming 200-250MB of data.
Unfortunately, the physicians used a filesystem (joliet or something
else) that I cannot mount. Even copying /dev/sr0 to file does not work.
The CD drive tries to read, stops, tries to read, stops. Over and over.
B.t.w., I have no windows machine to test with.
Anyone have an idea, how to check, what filesystem this is?

It's a Microsoft extension to iso9660.
http://www.faqs.org/docs/Linux-HOWTO/CDROM-HOWTO.html#AEN1328
There's also Rock Ridge ...
https://wiki.osdev.org/ISO_9660#Rock_Ridge_and_Joliet
Make sure your kernel is configured to support it ...
# zgrep CONFIG_JOLIET /proc/config.gz CONFIG_JOLIET=y
To create a cd with Rock Ridge...
# rpm -q -i xorriso|grep ^Sum Summary : ISO 9660 Rock Ridge
Filesystem Manipulator
# grep -e iso -e fat /etc/filesystems exfat iso9660 vfat
I got tired of replacing cd/dvd drives that stop working due to me being
a heavy smoker. Haven't used one in years, so don't remember all of the
details needed to work with them.
If I remember correctly, it must be mounted using vfat.
Regards, Dave Hodgins

Hi, thanks!

I checked the above, and a normal CD could be mounted with iso9660 and
the content was copied to harddisk in a few minutes.

But after that, I had to read in a DVD.
It was mounted as filesystem udf.

The first attempt to copy it was annoyingly slow. The more data already
was copied, the slower is was. I read similar experiences from people
running debian. After half an hour I gave up the attempt to copy around
900 MB. But after reloading and remounting, the data was copied in ~10
minutes. Maybe because they were cached. But anyway, this filesystem
seems to have severe problems with some DVDs.

So, again, many thanks for the info!

Best regards,

Markus