Cannot umount /usr filesystem (ALWAYS "busy")

[Chip Salzenberg]

According to rickf at pmafire.UUCP (rick furniss):
>If I recall correctly Unix was originally written on a PDP7, then to PDP11,
>[...]  These machines hardly had what one would consider large hard
>disks, and I believe still, /usr was part of root, the only partition.

Sorry -- you didn't beat the reaper.

The whole POINT of /usr/bin is that the root filesystem's /bin didn't
have room for all the Unix binaries.  Why else would there even BE a
/usr/bin, /usr/include, /usr/lib, etc?  The division between /bin and
/usr/bin and between /lib and /usr/lib would not have been worth the
trouble if everything fit in the root filesystem.

AT&T Unix from V7 (at least) mounts /usr.  Some others mount /u.
-- 
Chip Salzenberg at ComDev/TCT     <chip at tct.uucp>, <uunet!ateng!tct!chip>