I am using Ubuntu Intrepid Ibex and would like to update/upgrade Arch Linux which is on the other partition. I am double clicking the partition and it gets mounted at /media/disk then I am using the following commands in the terminal:
$ sudo chroot /media/disk
bash: /dev/null: Permission denied
# pacman -Syu
I just ignore the error message and type the pacman -Syu command.
Arch Linux gets updated and upgraded without running it.