It looks like a major bug exists in OpenFiler 2.99. I could not build a new RAID-1 array tonight on one of my file servers. A quick Google search revealed that a kernel module was not present, and an incorrect link must have been referenced somewhere. To fix it, follow these steps after you have SSHed into the console.
conary update mdadm=openfiler.rpath.org@rpl:devel/2.6.4-0.2-1
ln -s /sbin/lvm /usr/sbin/lvm
This information came from: http://www.everything-virtual.com/?p=349