In a RHEV environment, the KVMGuest agent uses REST APIs for virtual machine management in RHEV-M. The curl command is used for initiating REST APIs and the xpath command is used for parsing the results returned by the REST APIs. If you enable VCS to manage virtual machines in RHEV environment, you must ensure that the curl and xpath commands are available on all the hosts. Install the curl package for the curl command and install the perl-XML-XPath package for the xpath command.