Microsoft Windows installation to the absolute minimum to have more space for your penguin picture collection? Your Microsoft Windows stopped booting but you still need to get your half-finished PhD thesis off the hard drive? Or maybe you just want to install the latest and greatest Gentoo Linux on your new machine?
a lot of documentation in several languages.
The page on how to create customized versions of SystemRescueCD gives a few glimpses on how Gentoo is used here. (I'm also playing with a running version in a virtual machine while I type this. :) Basically the internal filesystem is a normal Gentoo x86 (i.e. 32bit userland) installation, with distfiles, portage tree, and some development files (headers etc.) removed to decrease disk space usage. (Skimming over the files in /etc/portage, the only really unusual thing which I can see is that >=gcc-4.5 is masked; the installed GCC version is 4.4.7- but who cares in this particular case.) After uncompressing the filesystem and re-adding the Gentoo portage tree, it can be used as a chroot, and (with some re-emerging of dependencies because of the deleted header files) packages can be added, deleted, or modified.
Downsides? Well, not much. Even if you select a 64bit Kernel on boot, the userland will always be 32bit. Which is fine for maximum flexibility and running on ancient hardware, but of course imposes the usual limits. And rsync then runs out of memory after copying a few TByte of data (hi Patrick)... :D
Want to try? Just emerge app-admin/systemrescuecd-x86 and you'll comfortably find the ISO image installed on your harddrive in /usr/share/systemrescuecd/.
From the /root/AUTHORS file in the rescue system:
SystemRescueCd (x86 edition)
* Main Author: Francois Dupoux
* Other contributors:
- Jean-Francois Tissoires (Oscar and many help for testing beta versions)
- Franck Ladurelle (many suggestions, and help for scripts)
- Pierre Dorgueil (reported many bugs and improvements)
- Matmas did the port of linuxrc for loadlin
- Gregory Nowak (tested the speakup)
- Fred alias Sleeper (Eagle driver)
- Thanks to Melkor for the help to port to unicode