On Tue, 6 Aug 1996, Markus Illenseer wrote:

>  Even though Unix is more than 2 decades old, it seems there is still
> no feasible mechanism to do a system check w/o being forced to shutdown
> to single user mode or umount all partitions.

This is not a trivial problem (because it's not a simple single-user OS).
I'm not sure there is a way to solve it without requiring an inordinate
amount of system time and/or resources.

One thing that I've found works fairly well, should this really be
necessary on occasion, is to modify /etc/rc to force a full check of the
disks on boot, and then reboot.  I usually revert it to the previous state
when I'm done, but there was one notable exception when I had some nasty
SCSI problems. 

--scott