<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Xen 3.4.1 Dom0 has been built via xen-3.1.4-4.src.rpm on top of F11 ( yum updated) This failure didn't happen with rc8 (or rc9), not sure. At the same time via my experience xend starts fine on the same 3.4.1 Dom0 (same 2.6.31 kernel) been built on top of F12 rawhide (yum updated). /etc/fstab contains 'xenfs' entry (3.4.1) in both cases and in both cases message /proc/xen is busy comes to console, however on F12 xend starts on F11 doesn't. I believe it makes sense to backport via xen-3.1.4-4.src.rpm CS 20185 plus some other CSs to make patching consistent (i cannot find out which ones) and get an option to remove 'xenfs' entry from /etc/fstab, mounting 'xenfs' at xend start up , what seems to be a default behaviour of the most recent 2.6.31 pvops enabled kernel. Boris. </td></tr></table>