By default, the Block Storage API service runs in one process. This limits the number of API requests that the Block Storage service can process at any given time. In a production environment, you should increase the Block Storage API throughput by allowing the Block Storage API service to run in as many processes as the machine capacity allows. The Block Storage API service is named openstack-cinder-api on the following distributions: CentOS, Fedora, openSUSE, Red Hat Enterprise Linux, and SUSE Linux Enterprise. In Ubuntu and Debian distributions, the Block Storage API service is named cinder-api. To do so, use the Block Storage API service option osapi_volume_workers. This option allows you to specify the number of API service workers (or OS processes) to launch for the Block Storage API service. To configure this option, open the /etc/cinder/cinder.conf configuration file and set the osapi_volume_workers configuration key to the number of CPU cores/threads on a machine. On distributions that include openstack-config, you can configure this by running the following command instead: # openstack-config --set /etc/cinder/cinder.conf \ DEFAULT osapi_volume_workers CORES Replace CORES with the number of CPU cores/threads on a machine.