When starting the computer today I found a bug in grub that prevented startup. The message is "error 24: attempt to access block outside partition". The grub failure with error code 24 indicates that failed to pass control to the partition because the login information is beyond the scope of the partition. Bizarre, considering that yesterday was not any work with hard drives and the system closed without problems. In any event has been very easy to solve and I'll share with you if you also happen.

First we start with the installation CD of Ubuntu 9.04 Jaunty Jackalope desktop. Once we are in the surroundings of gnome open a terminal from menu Applications → Accessories → Terminal.

In the terminal run:

sudo -i

for root and simplify the commands to be entered.

Then run:

fdisk -l

to know the partition with the system, ie "/". In my case "/ dev/sda5" but yours may be other than as "/ dev/sda1". Consequently you will have to change the path to keeping with your system.

We set the partition to access it:

mount /dev/sda5 /mnt

And finally reload the grub with:

sudo grub-install /dev/sda --root-directory=/mnt --recheck

Finally reboot the system from shutting down gnome or writing to the terminal:

reboot

Taking a brief look on the internet we can see that is a mistake that appears from ancient grub entry so it can not be said to be a failure attributable to ext4. Error in any case is not serious because even prevents us from accessing our system the data are safe in your hard drive.

Tell us if you have had this error with Jaunty and previous actions which you think might be the cause.