[linux-lvm] multi-disk vg?

[Chris Conn <cmcgoat@swbell.net>]

I've finally finished setting up my Slackware 9.1 box
with LVM and ReiserFS, here's what I've got:

disk 0 (one partition)
 
   /dev/mainvg/root          /
   (and swap space)

disk 1 (two partitions)

   /dev/rootvg/usr           /usr
   /dev/rootvg/var           /var
   /dev/rootvg/tmp           /tmp

   /dev/datavg/home          /home
   /dev/datavg/data          /data

I set up rootvg and datavg first and then last night
I followed the LVM How-To and converted the setup the
mainvg VG with root. All works well.

Now I'm wondering if I can merge mainvg and rootvg
as one VG though they're on two seperate disks. Is this
possible? And if so is it a good idea? 

BTW I left /etc in / because I had trouble mounting it
as a seperate filesystem with /etc/fstab.

Thanks for any advice, 

=====
Chris Conn   
cmcgoat@swbell.net   http://storm.cadcam.iupui.edu/~cmcgoat
Austin, TX