One last note on this, the upstream bug 1006386 should probably used as a reference for this problem as it really drills down to root cause of the slow journal access.
https://bugzilla.redhat.com/show_bug.cgi?id=1006386 -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org