To you and and also
a general remark to everyone:
If you have trouble booting a cd, if you get errors on boot, if the cd doesn't appear to be bootable and so on. The first thing to do is to check the integrity of the cd. There are two main methods:
- verify the checksum
- verify the burn
Checksums
This refers to the iso image. When ISOs are distributed, distros usually provide checksums so that you can verify that
the file on your disk is the same as the file on their server.
To give a concrete example.
from the ubuntu site, here is a mirror for the desktop iso:
ftp://ftp.free.fr/mirrors/ftp.ubuntu.com/releases/edgy/ubuntu-6.10-desktop-i386.iso
checksums are usually stored in the same directory, so try loading
ftp://ftp.free.fr/mirrors/ftp.ubuntu.com/releases/edgy/
In there you see a file called
MD5SUMS, open it. Notice the line
Code:
b950a4d7cf3151e5f213843e2ad77fe3 ubuntu-6.10-desktop-i386.iso
The first string is the checksum, the second is the name of the iso file. On your own system, do
Code:
$ md5sum ubuntu-6.10-desktop-i386.iso
b950a4d7cf3151e5f213843e2ad77fe3 ubuntu-6.10-desktop-i386.iso
And so you can see that the checksums match, you have verified the integrity of the file. There is a Windows version of md5sum, google it.
Checking the burn
This method can verify that
the iso you burnt on a cd was burnt correctly. It depends on your burn application, in k3b you do it like so:
- Tools > Burn CD Image...
- Check Verify written data
The burn will now take twice as long, because first you burn the image, then you read the whole disc to verify that it's the same.