This comes from the I-have-to-pay-my-electrical-bill and from the learn-something-fun-about-your-system-everyday-department. As you know I’ve got Gentoo on my workstation. When I still lived in my dorm it was running 24/7 (last but not least to supply everyone with the latest episodes of popular shows). When I moved I started using a hacked-together suspend-to-ram script which worked well enough for the last year or so. Seeing how quick and (seemingly easy) hibernate/suspend-to-disk worked on my new netbook I decided to once again give it a try on my workstation.
Since my system has one of those stupid fake-raids I have always needed an initrd to boot the kernel. The initrd calls dmraid, which maps the strange arrays into usable disk-devices (don’t ask me). The preferred way of creating an initrd with Gentoo is genkernel, which can be used to build a kernel as well. The only problem was that genkernel still lacks support for suspend (user-space suspend, see Gentoo Bug), while I can’t do without dmraid.
So I fired up git and started hacking on the genkernel-code and now have a system which does suspend-to-disk and dmraid. Having said that, I must stress that you should really know what you’re doing if you’re trying to use this. You could potentially shoot yourself in the foot if for some reason a hibernated image gets loaded after your harddrives have already been mounted. I try to avoid that in my patch by calling suspend_resume immediately after dmraid has been called (and only there). Improvements or constructive flames would be highly appreciated.