In my experience, it really is that simple.  Pop in the new drive and open up the Compaq Array Configuration Utility (under Compaq System Tools).  The new drive should show up but not be part of an array.  Just add it to the array and let it rebuild.  When it is done, you will need to add the free space you now have to a drive in your OS.  In NT, you would do this in Disk Administrator.  One time recently I ran into a problem with this on an NT server.  It said it couldn't add the free space because it already had 4 partitions.  It counts the F10 partition as one and the C drive and then someone had set up the D and E drives as primary partitions.  If these had been set up as an extended partition with D and E as logical drives within it, I would have been OK.  As it was, I had to copy the data off D to another server, blow the D drive away, recreate it as an extended partition and then add the free space to it and move the data back.  Other than this one glitch, though, I've never had any problems with this.

well, as you might guess, the drive went in without any problems at all....and I find myself with existing primary partitions so Im faced with the same routine.. Ill have to move all the data off and blow away the existing partition and start over looks like....

thanks again for the input...