[CentOS] newbie question on installation over existing Linux

Warren Young wrote:
> /usr was already assumed to be on the root FS in Solaris, FreeBSD

I'm using both Solaris and FreeBSD quite extensively and, honestly,
have never heard of that assumption. In fact, on the machine that I'm 
currently typing this message on, the file systems look like this:

    # uname -sr; mount -t ufs
    FreeBSD 10.1-RELEASE
    /dev/da0s1a on / (ufs, local, journaled soft-updates)
    /dev/da0s1d on /tmp (ufs, local, journaled soft-updates)
    /dev/da0s1e on /var (ufs, local, journaled soft-updates)
    /dev/da0s1f on /usr (ufs, local, journaled soft-updates)

(Everything else, especially /home, is NFS-mounted.)

Patrick