It enables code coverage of VDSM.
make
yum install vdsmcodecoverage
To enable
chkconfig vdsmcodecoveraged on
service vdsmcodecoveraged start
do what ever you want to do ... restart vdsm, reboot host, remove vdsm and then install vdsm back.
To disable
chkconfig vdsmcodecoveraged off
service vdsmcodecoveraged stop