Having a hard time copying root filesystem to new drive...

[Daniel B. Thurman]

Sigh... I pulled an all-nighter trying to copy my existing root filesystem
onto a new drive due to running out of filesystem space.  Seems that
I was able to cp -a the existing drive to my new filesystem partition,
was able to properly setup the fstab, relabel, and so on, was able
to see grub working but when it came to starting up the new drive,
I get the following errors:

....blah....blah
Uncompressing Linux... Ok, booting the kernel.
Red Hat nash version 6.0.19 starting
Unable to access resume device (LABEL=SWAP-sda3)  <- have to rebuild the initrd file....
mount: could not find filesystem '/dev/root'
setuproot: moving /dev failed: No such file or directory
setuproot: error mounting /proc
setuproot: error mounting /sys: No such file or directory
switchroot: mount failed: No such file or directory
[hang]

What am I doing wrong?
More importantly, what is the proper procedure in making a copy of your
existing root filesystem onto a new drive partition?

Thanks!
Dan