is there a simple way to check a live CD for errors?

Question

I was trying to use 2 methods "HOWTOMD5SUM" and "HOWTOSHA256SUM", but they are all way complicated for a newbie. Is there an application that could do the same in a simple way? I've already tried "checksum calculator" too, but it seems to work on iso files, not on live CDs.

Answer 1

How about choosing the "Check CD for defects" from the boot menu? :)

This is an screenshot from an old Ubuntu version, in newer versions you have to hit Enter during the boot process when you see this screen to see this menu:

Answer 2

md5 checking is not only used to check for errors, but to check for authenticity. You could have a cd that does not have errors, but that is non-authentic... ie., a hacked copy. It could also be a case that your download did not complete properly. It is possible to use the md5sum to ensure that what you are burning is valid and a complete copy. If you had an .iso that was not valid you could end up with a CD that would not boot (depends on where the error was in the downloaded file).

To check the md5sum of the .iso file you would:

md5sum nameoffile.iso

example:

$ md5sum precise-server-amd64.iso
6cac02eb0b97633d3db3c86f1cf9a117  precise-server-amd64.iso

You then take the result - 6cac02eb0b97633d3db3c86f1cf9a117 and compare it to themd5sum listed on the download page.

example: http://cdimage.ubuntu.com/daily-live/current/

59e51de80a7a047841fbe59521720e89 *precise-server-amd64+mac.iso
76e88c3e5dcfd5c887b1668cf2f26867 *precise-server-amd64.iso
eb8afa349ad92ad7c3c8088a94b5937b *precise-server-i386.iso
79d52f0ad383a53bffee7ccce909205c *precise-server-powerpc.iso

You can see that the md5sum is not the same as the one I generated. These are from daily builds so this is to be expected.