One of my NSLU2′s went up the swanny two weeks back. Typically it was the one 80 miles away at home, that not only is my primary mail exchanger but also the DHCP server for my home network, chances are somebody might notice. Thankfully I have the ability to fail over DHCP onto sandman with a one line configuration change and a restart of dnsmasq, which I did.
Whilst I was at home this past week I got to work trying to work out what was up. The documentation in Debian about the LED sequences told me that it was getting stuck at the initramfs stage of boot. Basically it couldn’t load the actual operating system off the discs. This meant I would have to delve deep and play with the contents of the flash memory.
I mounted the USB sticks that I use as its discs on my server and extracted a copy of the current kernels and initramfs images that were on it. I also found the Debian installation flash firmware and set about hacking the two. I found some instructions on how to modify an existing image which is what I did. I swapped out the kernel and initramfs in the firmware for the latest ones on my discs and flashed the NSLU2. Same thing happened! So I then set about using the previous kernel version which worked like a charm. For now I have removed the new kernel from it and forced it to keep the old version. I will look into updating it when I have a little more time.