Setup:
Build System and mirror data + partition.
(e.g. dd if=/dev/sda of=/dev/sdb conv=noerror bs=4k)
Mount sdb partitions weekly and rsync w/sda.
This gives us a full backup of the system locally protecting us against both hardware and software/user errors.

Problem:
Current setup is calling for the use of LVM for /home and /var. Since logical volumes are mounted w/o an independent drive letter/number specification (eg. /dev/VG/lv-home as opposed to /dev/sdb1 and /dev/sda1), I cannot figure out how I would go about mounting both the original and the backup version so that I can keep them synced.

The idea is to have a backup that is exactly as the original was a few days prior that we can pull and and boot from if needed. Any suggestions on how to get around this LVM issue is greatly appreciated.