You can enable and disable Compute services. The following examples disable and enable the nova-compute service. List the nova services: $ nova service-list +------------------+----------+----------+---------+-------+----------------------------+-----------------+ | Binary | Host | Zone | Status | State | Updated_at | Disabled Reason | +------------------+----------+----------+---------+-------+----------------------------+-----------------+ | nova-conductor | devstack | internal | enabled | up | 2013-10-16T00:56:08.000000 | None | | nova-cert | devstack | internal | enabled | up | 2013-10-16T00:56:09.000000 | None | | nova-compute | devstack | nova | enabled | up | 2013-10-16T00:56:07.000000 | None | | nova-network | devstack | internal | enabled | up | 2013-10-16T00:56:06.000000 | None | | nova-scheduler | devstack | internal | enabled | up | 2013-10-16T00:56:04.000000 | None | | nova-consoleauth | devstack | internal | enabled | up | 2013-10-16T00:56:07.000000 | None | +------------------+----------+----------+---------+-------+----------------------------+-----------------+ Disable a nova service: $ nova service-disable localhost.localdomain nova-compute --reason 'trial log' +----------+--------------+----------+-------------------+ | Host | Binary | Status | Disabled Reason | +----------+--------------+----------+-------------------+ | devstack | nova-compute | disabled | Trial log | +----------+--------------+----------+-------------------+ The Havana release introduces the optional --reason parameter that enables you to log a reason for disabling a service. Check the service list: $ nova service-list +------------------+----------+----------+---------+-------+----------------------------+------------------+ | Binary | Host | Zone | Status | State | Updated_at | Disabled Reason | +------------------+----------+----------+---------+-------+----------------------------+------------------+ | nova-conductor | devstack | internal | enabled | up | 2013-10-16T00:56:48.000000 | None | | nova-cert | devstack | internal | enabled | up | 2013-10-16T00:56:49.000000 | None | | nova-compute | devstack | nova | disabled | up | 2013-10-16T00:56:47.000000 | Trial log | | nova-network | devstack | internal | enabled | up | 2013-10-16T00:56:51.000000 | None | | nova-scheduler | devstack | internal | enabled | up | 2013-10-16T00:56:44.000000 | None | | nova-consoleauth | devstack | internal | enabled | up | 2013-10-16T00:56:47.000000 | None | +------------------+----------+----------+---------+-------+----------------------------+-----------------+ Enable the service: $ nova service-enable localhost.localdomain nova-compute +----------+--------------+---------+ | Host | Binary | Status | +----------+--------------+---------+ | devstack | nova-compute | enabled | +----------+--------------+---------+ Check the service list: $ nova service-list +------------------+----------+----------+---------+-------+----------------------------+-----------------+ | Binary | Host | Zone | Status | State | Updated_at | Disabled Reason | +------------------+----------+----------+---------+-------+----------------------------+-----------------+ | nova-conductor | devstack | internal | enabled | up | 2013-10-16T00:57:08.000000 | None | | nova-cert | devstack | internal | enabled | up | 2013-10-16T00:57:09.000000 | None | | nova-compute | devstack | nova | enabled | up | 2013-10-16T00:57:07.000000 | None | | nova-network | devstack | internal | enabled | up | 2013-10-16T00:57:11.000000 | None | | nova-scheduler | devstack | internal | enabled | up | 2013-10-16T00:57:14.000000 | None | | nova-consoleauth | devstack | internal | enabled | up | 2013-10-16T00:57:07.000000 | None | +------------------+----------+----------+---------+-------+----------------------------+-----------------+