Actually, it can be done. In 50-udev.rules, Red Hat has an OPTIONS+=”ignore_device” rule for dm-* devices, which would normally completely ignore them. But if you place your dm-* rules in a file which executes prior to 50-udev (use 49 or lower). Then create the raw device (Note that you can’t add a raw0, so you can’t just create /dev/raw/raw$MINOR…so add one to the minor number first):
RUN+=”/bin/sh -c ‘/bin/raw /dev/raw/raw$((MINOR + 1)) $MAJOR $MINOR’”

Finally, add add OPTIONS+=”last_rule” at the end of your rules, it will bypass future rules.

This creates a /dev/raw/raw# node, but in order to make raw device names “prettier”, you can add another set of rules to execute on: ACTION==”add”, KERNEL==”raw[0-9]*” to determine the vg and lv names and add a /dev/raw-mapper/* symlink (“$vg-$lv”, or the WWID for example): SYMLINK+=”raw-mapper/%c{1}”

I have discovered a truly marvelous demonstration of this proposition that this textarea is too narrow to contain.