I have been dreading the prospect of sitting through an Gentoo upgrade on my old 333MHz Celeron system. It's mostly used as an X terminal to log into one of the other faster machines so it wasn't bothering me too much. But the longer I put it off, the worse it was going to be when I finally got around to it.
I had been thinking of NFS mounting the root partition from one of my other machines and chrooting into it to do the upgrade. I finally bit the bullet and decided to try it after finding someone else that did it successfully. I started emerge this morning and it's half done using my new AMD X2 4200 as the build engine.
Distcc doesn't quite cut it in this situation. Only the compilation step is offloaded with distcc. This machine is too slow to feed multiple compilation hosts with preprocessed source. It can't keep my other machines busy while it consumes 100% of its own processor just doing precompilation.
Distcc can also be turned off by certain ebuilds but that may not stop make from honoring the '-j5' you stuck in make.conf. That means this lowly 333MHz Celeron with 320MB of RAM is now executing 5 simultaneous builds on its own.
It would be nice if some additional steps could be offloaded. I did a test yesterday between my 700MHz P3 and the new machine. I compressed a large text file on the P3 and timed it. I then used ssh to fire up the compressor on the X2 and return the compressed file to the P3. The X2 was 3x as fast even though the data made two trips across the network through an encrypted channel.
Anyway, this has been a significant improvement for upgrading this machine. I have already set up a run-level to turn off unnecessary services on the Celeron. I'll set up some scripts to do the mounts required from the X2 and maybe this machine will stay somewhat updated from now on.