Just installing Fedora 16 on a new system. We set up a RAID1 with mdadm for /. This is standard mdraid, created with anaconda during F16 install. On boot, we're finding that if there is a RAID inconsistency, dracut is waiting for mdadm reconstruction to complete before booting the system. This means that after a power outage or other condition that would cause a reconstruction to become necessary, we have to wait several hours for the system to come online again. My understanding is that this reconstruction is a background task, is there really a need for this to hold up boot? This behaviour comes from 0064-90mdraid-wait-for-md-devices-to-become-clean.patch in the dracut-013-19.fc16 package.
Note that kernel mdraid is specifically designed to allow operation while the array is rebuilding.