teh fear

Everytime I need to change something on a co-located server (ours are only about 2 miles from the main office, but it is still a pain if one has to go to the site because a server is not booting up) that requires restarting in a new configuration, I’m always worried that something might not [...]

A file, key to the successful boot of many a linux system is the initrd image.
It used to be a simple gzipped loop filesystem, unpacked and mounted by commands similar to
gzip -dc initrd.img > initrd_unzipped.img
mount -o loop initrd_unzipped.img temp_dir
Then files can be tweaked inside ‘temp_dir’, the image is then updated by
umount temp_dir
gzip -9c initrd_unzipped.img > [...]