How does one run unix from ram-disk???

[David Cole]

I'm trying to boot BSD or Linux from a CD,
and then load a ram-disk from the CD, 
with BSD/Linux and Apache and Sendmail,  
and then run Apache and Sendmail from the 
ram-disk.
   I can burn the bootable unix CD and copy 
to the ramdisk.

*   But how do you point/transfer the running 
operating system to run out of the ram-disk???

   Is there a way to switch root to the ram-disk???

   Is there a way to switch which HD is root???

   Or Is there a way to do something like a 
warm boot into the ram-disk???

   I would prefer to not end up with a read-only 
operating system that a CD gives me.

Thanks
David Cole
metalgrow at cds1.net
707-833-2551