Existing Reiser4 partitions - CAREFUL!
I have an existing Gentoo install with 3 reiser4 partitions /, /home, and /media. When trying Sabayon on a spare partition, I noticed the installer thought /media was swap, but was marked as leaving the data untouched so I wasn't too worried. However, on reboot, Sabayon mounted it as swap, destroying the file system, so when I eventually booted back into Gentoo, it was gone: unrecognized and unmountable. fsck.reiser4 was not working from within Gentoo, but rebooting to the old Conrad disc I had installed from and running it happily saved tons of data by running it with --build-sb and then --build-fs as it asked for. A happy ending to a stressful few minutes - backup and keep a sharp eye on that installer.