08/04/30 19:15:10 0fwu15uN
最近Gentooインストールしたんでそのときこんなこと書いてありました。
The sixth field is used by fsck to determine the order in which filesystems
should be checked if the system wasn't shut down properly.
The root filesystem should have 1 while the rest should have 2 (or 0 if a filesystem check isn't necessary).