Since RHEL 6.1 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.

The reproducer is similar to that of bug 681459:

1. create two transient (using virsh create) qemu domains with the following
   UUIDs:
   dom1: d5b3e8ff-2be6-4f81-a23e-6ec94f2338db and
   dom2: f0b4f8f7-0a56-4a76-ab7d-522bbe32ada3
   (the exact UUIDs are crucial since they need to be mapped to the same
   hash key so that the two objects form a linked list within the hash)
2. stop libvirtd service
3. kill the qemu processes corresponding to dom1 and dom2
5. start libvirtd service
   the deamon should crash or hang once it detects that it cannot connect to 
   those domains

POST: http://post-office.corp.redhat.com/archives/rhvirt-patches/2011-April/msg00346.html

The bug has been verified on libvirt-0.8.7-18.el6.x86_64

Followed the steps #comment3, 
# service libvirtd stop
Stopping libvirtd daemon:                                  [  OK  ]

# kill `pgrep qemu`

# service libvirtd start
Starting libvirtd daemon:                                  [  OK  ]

# service libvirtd status
libvirtd (pid  13316) is running...

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2011-0596.html