these error messages indicate that the system is still trying to access some files on the CD, and are harmless except that they obscure the message asking the user to press Enter to reboot. You can safely remove the CD from the tray and press Enter at this point to reboot to your new Ubuntu system. (539027)
Documented at <https:/ /wiki.ubuntu. com/LucidLynx/ ReleaseNotes# I/O%20error% 20after% 20CD%20is% 20ejected% 20at%20end% 20of%20install>:
In some cases, ejecting the CD at the end of installation will leave errors on the screen such as:
end_request: I/O error, dev sr0, sector 437628
these error messages indicate that the system is still trying to access some files on the CD, and are harmless except that they obscure the message asking the user to press Enter to reboot. You can safely remove the CD from the tray and press Enter at this point to reboot to your new Ubuntu system. (539027)