I have a (really old) system which has two identical 1G drives (wd0 and wd1)
and an 8G drive (wd2).  I keep / and such on wd0 and /usr on wd2.

I tried this to make a copy of wd0 on wd1:

    dd if=/dev/wd0d of=/dev/wd1d

This seems to work, but are there any issues about not being in single user
mode or having stuff mounted on wd0 that are going to bite me later?

Also, I'd like to set up a Raid1 set on wd0 and wd1 (note that wd0 is the
normal boot device).  I thought there was a HOWTO on this somewhere, but 
Google can't seem to dredge it up and I can't remember where I think I
saw it.  Was I imagining things?

Michael D. Spence 
Mockingbird Data Systems, Inc.