[email protected]:~# gedit /var/log/nova/nova-conductor.log
[email protected]:~# gedit /var/log/nova/nova-scheduler.log
\2018-03-15 14:20:35.913 1140 INFO nova.filters [req-72a6c461-d33b-4e71-a150-24c397765105 be65496d92cf4f0cad11a8f286bb64ef 9f2840ce18fe4e6889ee98f85f2fb724 - - -] Filter RetryFilter returned 0 hosts
2018-03-15 14:20:35.913 1140 INFO nova.filters [req-72a6c461-d33b-4e71-a150-24c397765105 be65496d92cf4f0cad11a8f286bb64ef 9f2840ce18fe4e6889ee98f85f2fb724 - - -] Filtering removed all hosts for the request with reservation ID ‘r-x0rha8v8‘ and instance ID ‘21e45ab4-3f95-4ad7-8786-5cbf472a7209‘. Filter results: [‘RetryFilter: (start: 0, end: 0)‘]
2018-03-15 13:38:06.896 2886 WARNING nova.scheduler.utils [req-55e7065b-bdce-4aec-bbb1-49ae625ce98f be65496d92cf4f0cad11a8f286bb64ef 9f2840ce18fe4e6889ee98f85f2fb724 - - -] Failed to compute_task_build_instances: No valid host was found. There are not enough hosts available.
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/oslo_messaging/rpc/server.py", line 142, in inner
return func(*args, **kwargs)
File "/usr/lib/python2.7/dist-packages/nova/scheduler/manager.py", line 84, in select_destinations
filter_properties)
File "/usr/lib/python2.7/dist-packages/nova/scheduler/filter_scheduler.py", line 90, in select_destinations
raise exception.NoValidHost(reason=reason)
NoValidHost: No valid host was found. There are not enough hosts available.
[email protected]:~# gedit /etc/nova/nova.conf
scheduler_default_filters=AllHostsFilter
原文地址：https://www.cnblogs.com/youran-he/p/8573453.html