View Full Version : [all variants] FYI - you can't rely on "Check CD for Defects"

December 12th, 2008, 01:56 AM
There is clearly a bug in the test process used by the Alternate CD (and normal LiveCD, too?) for "Check CD for defects". You can have a perfectly valid disc but a flaky drive and the test will Pass -- but your install will still fail!

I just experienced this firsthand and wanted to report it!

I had an existing system with 8.04, everything was running beautifully. I downloaded the 8.10 Alternate ISO and burned it to disc. I shutdown, installed a brand-new hard-drive, then booted from the CD and tried to install it; the process failed after the "Checking APT sources" step. I tried several times, changing various install (and BIOS) options each time, but it always failed in the same spot. I suspected the disc and ran "Check CD for defects" -- it passed. Mind you, this was all being done on the same PC and CD drive, start to finish.

Ultimately, I realized the CD drive was about 3 years-old and I had another that was less than 1 year-old. So I swapped them and now the install worked perfectly.

The Ubuntu installer seems to be very sensitive to minor problems in CD/DVD drives. The "Check for CD defects" seems to be less sensitive to those same problems and reports a false negative (for problems).

December 12th, 2008, 02:23 AM
Have you checked for a launchpad bug?

If there isn't one, you may want to post this as one.

March 7th, 2009, 01:30 AM
So, I reported this via Launchpad but no one ever responded...