Peter: > I'm thinking of separating /usr onto its own partition so that I can have it > mounted read-only except while updating it. I'd prefer not to have to make an > init thingy, not having needed one up to now. Besides, some machines have > things like early-ucode or amd-uc. > > I've found a few guides on the Web, but I'm still confused. Is there a simple > guide to doing this? I know of at least one subscriber here who's done it. :)
I'm using separate /usr, it was the default historically and I just continued useing it, partly because it is unconvenient to repartion long running remote systems. There are a few things to look out for. If you are not using initrd/initramfs, you need all drivers to access / to be compiled in. Easiest is if don't use devices with dynamic minors. Once / is mounted you have all drivers available in /lib/modules, then the next possible hurdle is to survive long enought till /usr is mounted. For that you a suitable mount command which does not depend on /usr, i.e. it or any programs previous it in the bootup cannot depend on libs in /usr. The easiest way to accomplish that is to use busybox. It is also possible to use sys-fs/static-dev, if you want to opt to not use udev. Regards, /Karl Hammar
