I have a set of identical hardware, Dell R210s. To replicate their configuration, I use a method to image /dev/sda from a working machine, and then apply that image to a new machine. It has been accomplished many times without a hitch.
As root on the machine to be cloned...
dd if=/dev/zero of=/tmp/0bits bs=20M; rm -f /tmp/0bits
Boot from a DVD (I use knoppix 6.7) and image the disk...
dd if=/dev/sda | gzip - | ssh user@hostname dd of=image.gz
Then boot the destination with the DVD, and overlay the image...
ssh user@hostname dd if=image.gz | gunzip - | dd of=/dev/sda
All of the success to date has been with RHEL 5.x and RHEL 6.x. I attempted the same method for RHEL 7.x for the first time and have received the following error when I boot from /dev/sda afterward...
[ 1.659252] i8042: No controller found
I do not receive the error if I reboot using the knoppix DVD, but I do receive the error if I attempt to boot using a RHEL 7 installation DVD or the internal hard drive.
I've seen "solutions" on Ubuntu forums which suggest the you add nomodeset to the boot parameters. This does not affect the error in my case.