I'm copying some data CDs/DVDs to ISO files to use them later without the need of them in the drive.
I'm looking on the Net for procedures and I found a lot:
catto copy a medium: http://www.yolinux.com/TUTORIALS/LinuxTutorialCDBurn.html
cat /dev/sr0 > image.iso
ddto do so (apparently the most widely used): http://www.linuxjournal.com/content/archiving-cds-iso-commandline
dd if=/dev/cdrom bs=blocksize count=count of=/path/to/isoimage.iso
Use of just
pvto accomplish this: See
man pvfor more information, although here's an excerpt of it:
Taking an image of a disk, skipping errors: pv -EE /dev/sda > disk-image.img Writing an image back to a disk: pv disk-image.img > /dev/sda Zeroing a disk: pv < /dev/zero > /dev/sda
I don't know if all of them should be equivalent, although I tested some of them (using the
md5sum tool) and, at least,
pv are not equivalent. Here's the
md5sum of both the drive and generated files using each procedure:
md5 of dd procedure:
md5 of pv procedure:
EDIT: That output was from another CD than the output given. In fact, I realized there are some interesting facts I provide as an answer.
In fact, the size of each file is different comparing to each other.
So, is there a best procedure to copy a CD/DVD or am I just using the commands incorrectly?
More information about the situation
Here is more information about the test case I'm using to check the procedures I've found so far:
isoinfo -d i /dev/sr0
dd to copy the media, with output checksums and file information
pv to copy the media, with output checksums and file information
Any help will be appreciated!