在/etc/nova/nova.conf的scheduler塊：
[scheduler]
9597
9598 #
9599 # From nova.conf
9600 #
9601
9602 #
9603 # The class of the driver used by the scheduler. This should be chosen from one
9604 # of the entrypoints under the namespace 'nova.scheduler.driver' of file
9605 # 'setup.cfg'. If nothing is specified in this option, the 'filter_scheduler' is
9606 # used.
9607 #
9608 # Other options are:
9609 #
9610 # * 'caching_scheduler' which aggressively caches the system state for better
9611 # individual scheduler performance at the risk of more retries when running
9612 # multiple schedulers. [DEPRECATED]
9613 # * 'chance_scheduler' which simply picks a host at random. [DEPRECATED]
9614 # * 'fake_scheduler' which is used for testing.
9615 #
9616 # Possible values:
9617 #
9618 # * Any of the drivers included in Nova:
9619 #
9620 # * filter_scheduler
9621 # * caching_scheduler
9622 # * chance_scheduler
9623 # * fake_scheduler 假借的調度器，用於測試
9624 #
9625 # * You may also set this to the entry point name of a custom scheduler driver,
9626 # but you will be responsible for creating and maintaining it in your
9627 # setup.cfg
9628 # file.
9629 #
目前不明白setup.cfg是哪裏的？