目录：（可以按w快捷键切换大纲视图）
- 故障处理流程
- 创建vm报错
- neutron服务是好的，命令行创建网络查看网络正常，就是dashboard不能查看网络相关的页面
- 查看中文命名的镜像的时候，报错
- vm 生成失败
- 疏散失败
- 有一定的概率无法显示控制台
- 在dashboard界面上，用镜像centos7、flavor–2，创建虚机error。并且抛出的错误是no host，即没有找到合适的调度节点。
- import error
- keystone报错
- re-scheduled: Not authorized for image
- libvirtError: unsupported configuration: IDE controllers are unsupported for this QEMU binary or machine type
- qemu-kvm: Cirrus VGA not available
- 默认路由不能删除
- dashboard访问卡顿
- task_state一直处于scheduling
- Access denied for user ‘nova’@’%’ to database ‘nova_api’
- 所有节点disk不足，返回0可用host
- novnc打不开问题定位
- qemu-ga由于找不到对应的虚拟串行字符设备而启动失败，提示找不到channel
故障处理流程
- 首先确定故障的资源ID，并判断故障发生的组件
- 查看对应组件的日志，根据故障资源ID进行搜索，找到相应的ERROR日志
- 如果ERROR日志又将问题指向了其他组件，则根据ERROR日志中的资源ID、时间、req-id等信息，其他组件继续查找问题，直到发现问题根源。
- 如果没有在日志中发现任何ERROR，有可能是网络不通，导致请求无法到达API，此时需要检查和API的连通性（如果使用VIP的话，需要分别检查和VIP的联通性和实IP的连通性）。
- 如果API中能找到相应请求，但是conductor/scheduler/compute没有找到相应日志，则有可能是MQ发生故障。
- 如果组件长时间没有任何日志刷新，有可能是组件进程挂掉或者处于僵死状态，可以尝试重启服务，或先打开Debug再重启服务。（对线上环境，重启服务操作需要首先报备，经甲方同意后再操作！）
创建vm报错
[root@EXTENV-194-18-2-16 nova]# cat nova-compute.log | grep 620cd801-8849-481a-80e0-2980b6c8dba6
2018-08-23 15:23:36.136 3558 INFO nova.compute.resource_tracker [req-f76d5408-00f8-4a67-854e-ad3da2098811 - - - - -] Instance 620cd801-8849-481a-80e0-2980b6c8dba6 has allocations against this compute host but is not found in the database.
分析：感觉是node的信息数据库不同步
nova show 出错的vm，包cell错误
####每次增加一个计算节点在控制节点需要执行：
# su -s /bin/sh -c "nova-manage cell_v2 discover_hosts --verbose" nova
问题解决。
neutron服务是好的，命令行创建网络查看网络正常，就是dashboard不能查看网络相关的页面
dashboard 网络页面报错 Invalid service catalog service: network
分析：应该是Keystone没有正常配置。导致没有找到相关的Catalog信息。
[root@EXTENV-194-18-2-11 ~]# openstack catalog list
+-----------+-----------+-----------------------------------------------+
| Name | Type | Endpoints |
+-----------+-----------+-----------------------------------------------+
| placement | placement | RegionOne |
| | | internal: http://nova-ha-vip:8778 |
| | | RegionOne |
| | | admin: http://nova-ha-vip:8778 |
| | | RegionOne |
| | | public: http://nova-ha-vip:8778 |
| | | |
| keystone | identity | RegionOne |
| | | public: http://keystone-ha-vip:5000/v3/ |
| | | RegionOne |
| | | internal: http://keystone-ha-vip:35357/v3/ |
| | | RegionOne |
| | | admin: http://keystone-ha-vip:35357/v3/ |
| | | |
| glance | image | RegionOne |
| | | admin: http://glance-ha-vip:9292 |
| | | RegionOne |
| | | internal: http://glance-ha-vip:9292 |
| | | RegionOne |
| | | public: http://glance-ha-vip:9292 |
| | | |
| nova | compute | RegionOne |
| | | public: http://nova-ha-vip:8774/v2.1 |
| | | RegionOne |
| | | admin: http://nova-ha-vip:8774/v2.1 |
| | | RegionOne |
| | | internal: http://nova-ha-vip:8774/v2.1 |
| | | |
| neutron | network | |
| neutron | network | RegionOne |
| | | public: http://neutron-server-ha-vip:9696 |
| | | RegionOne |
| | | admin: http://neutron-server-ha-vip:9696 |
| | | RegionOne |
| | | internal: http://neutron-server-ha-vip:9696 |
| | | |
+-----------+-----------+-----------------------------------------------+
所以把第一条没有url的数据删掉就好了，但是发现只有openstack catalog list，没有openstack catalog delete命令，后来查看keystone的配置文件keystone.conf发现如下配置
见[catalog]
从配置文件和一些资料看出catalog是从mysql里面读取的数据，然后从mysql的keystone库中的service表里找到了脏数据，然后知道了用openstack service delete去删除‘脏数据’，问题就解决了。
MariaDB [keystone]> select * from service;
+----------------------------------+-----------+---------+-------------------------------------------------------------+
| id | type | enabled | extra |
+----------------------------------+-----------+---------+-------------------------------------------------------------+
| 520f6bf8564240be9678c4ef25305cad | placement | 1 | {"description": "OpenStack Placement", "name": "placement"} |
| 960580852a594c078e68fe3683e35db5 | identity | 1 | {"name": "keystone"} |
| 98ed18fcd8104732919bb5869a5a6dc2 | image | 1 | {"description": "OpenStack Image", "name": "glance"} |
| abef1b9469d94d3ab9f27c8ed72a5a48 | compute | 1 | {"description": "OpenStack Compute", "name": "nova"} |
| e37085e8fb2a49c0921c2d24f5e4f9b5 | network | 1 | {"description": "OpenStack Networking", "name": "neutron"} |
| f1b661407ce04f79bc24605fa59bb74c | network | 1 | {"description": "OpenStack Networking", "name": "neutron"} |
+----------------------------------+-----------+---------+-------------------------------------------------------------+
6 rows in set (0.00 sec)
MariaDB [keystone]> select * from endpoint;
+----------------------------------+--------------------+-----------+----------------------------------+-----------------------------------+-------+---------+-----------+
| id | legacy_endpoint_id | interface | service_id | url | extra | enabled | region_id |
+----------------------------------+--------------------+-----------+----------------------------------+-----------------------------------+-------+---------+-----------+
| 142cb619cd2242828b0c9394d5baaea1 | NULL | public | f1b661407ce04f79bc24605fa59bb74c | http://neutron-server-ha-vip:9696 | {} | 1 | RegionOne |
| 2252d3ef840b4c5aa1184ebe8d6094f1 | NULL | public | abef1b9469d94d3ab9f27c8ed72a5a48 | http://nova-ha-vip:8774/v2.1 | {} | 1 | RegionOne |
| 476654c6e7dd4d22b290de451e3afda0 | NULL | admin | abef1b9469d94d3ab9f27c8ed72a5a48 | http://nova-ha-vip:8774/v2.1 | {} | 1 | RegionOne |
| 562a5d5443af4dfab6760204d0adf3bf | NULL | internal | 520f6bf8564240be9678c4ef25305cad | http://nova-ha-vip:8778 | {} | 1 | RegionOne |
| 58bd5f09811a4ebcb62a4b51fb7ae444 | NULL | admin | f1b661407ce04f79bc24605fa59bb74c | http://neutron-server-ha-vip:9696 | {} | 1 | RegionOne |
| 600811f8ccaf42669d4d83b897af3933 | NULL | admin | 520f6bf8564240be9678c4ef25305cad | http://nova-ha-vip:8778 | {} | 1 | RegionOne |
| 80683f619efb41dcbb6796ea04f16159 | NULL | internal | f1b661407ce04f79bc24605fa59bb74c | http://neutron-server-ha-vip:9696 | {} | 1 | RegionOne |
| 8e0a684607294a729f87d7d8b1a639ca | NULL | public | 520f6bf8564240be9678c4ef25305cad | http://nova-ha-vip:8778 | {} | 1 | RegionOne |
| 9ef0f18d891e45608ffc41985dc6afa6 | NULL | public | 960580852a594c078e68fe3683e35db5 | http://keystone-ha-vip:5000/v3/ | {} | 1 | RegionOne |
| a0b10cb04a5b4ca3859aaf2ea4ca2a3b | NULL | admin | 98ed18fcd8104732919bb5869a5a6dc2 | http://glance-ha-vip:9292 | {} | 1 | RegionOne |
| c53979becccc44f1813e9f50a619af7e | NULL | internal | 960580852a594c078e68fe3683e35db5 | http://keystone-ha-vip:35357/v3/ | {} | 1 | RegionOne |
| dadbb8dc218245bbba8c9a34237413ec | NULL | internal | 98ed18fcd8104732919bb5869a5a6dc2 | http://glance-ha-vip:9292 | {} | 1 | RegionOne |
| f4034b8c086a451caed52ac51a761fb0 | NULL | public | 98ed18fcd8104732919bb5869a5a6dc2 | http://glance-ha-vip:9292 | {} | 1 | RegionOne |
| fc150884825544baaf4912f14e76f51a | NULL | internal | abef1b9469d94d3ab9f27c8ed72a5a48 | http://nova-ha-vip:8774/v2.1 | {} | 1 | RegionOne |
| fc7132052063438895674fd7b840db68 | NULL | admin | 960580852a594c078e68fe3683e35db5 | http://keystone-ha-vip:35357/v3/ | {} | 1 | RegionOne |
+----------------------------------+--------------------+-----------+----------------------------------+-----------------------------------+-------+---------+-----------+
15 rows in set (0.00 sec)
[root@EXTENV-194-18-2-11 ~]# openstack service list
+----------------------------------+-----------+-----------+
| ID | Name | Type |
+----------------------------------+-----------+-----------+
| 520f6bf8564240be9678c4ef25305cad | placement | placement |
| 960580852a594c078e68fe3683e35db5 | keystone | identity |
| 98ed18fcd8104732919bb5869a5a6dc2 | glance | image |
| abef1b9469d94d3ab9f27c8ed72a5a48 | nova | compute |
| e37085e8fb2a49c0921c2d24f5e4f9b5 | neutron | network |
| f1b661407ce04f79bc24605fa59bb74c | neutron | network |
+----------------------------------+-----------+-----------+
[root@EXTENV-194-18-2-11 ~]# openstack service delete e37085e8fb2a49c0921c2d24f5e4f9b5
[root@EXTENV-194-18-2-11 ~]# systemctl restart httpd.service memcached.service
查看中文命名的镜像的时候，报错
[root@NFJD-TESTVM-CORE-API-1 ~]# glance image-list
'ascii' codec can't encode character u'\u5982' in position 1242: ordinal not in range(128)
分析：镜像名字有用中文命名的情况。
将export LC_ALL=zh_CN.UTF-8
添加到/etc/profile
同时注意source的文件中是否有export LC_ALL=C
vm 生成失败
2017-05-25 11:01:29.577 21880 TRACE nova.compute.manager [instance: 2c5a8e62-62d0-430d-8747-795350bb6939] ProcessExecutionError: Unexpected error while running command.
2017-05-25 11:01:29.577 21880 TRACE nova.compute.manager [instance: 2c5a8e62-62d0-430d-8747-795350bb6939] Command: qemu-img convert -O raw /var/lib/nova/instances/_base/f5797db00aacfbe240bbfb0f53c2da80e4be6dfc.part /var/lib/nova/instances/_base/f5797db00aacfbe240bbfb0f53c2da80e4be6dfc.converted
2017-05-25 11:01:29.577 21880 TRACE nova.compute.manager [instance: 2c5a8e62-62d0-430d-8747-795350bb6939] Exit code: 1
2017-05-25 11:01:29.577 21880 TRACE nova.compute.manager [instance: 2c5a8e62-62d0-430d-8747-795350bb6939] Stdout: u''
2017-05-25 11:01:29.577 21880 TRACE nova.compute.manager [instance: 2c5a8e62-62d0-430d-8747-795350bb6939] Stderr: u'qemu-img: error while writing sector 1569792: No space left on device\n'
2017-05-25 11:01:29.577 21880 TRACE nova.compute.manager [instance: 2c5a8e62-62d0-430d-8747-795350bb6939]
2017-05-25 11:01:29.580 21880 INFO nova.compute.manager [req-9fa74abf-bcc1-4b7e-aaef-2e17b593a356 6aa5df16b47442c58efde791abd60497 66458b9ead64409fb9d2e0f2c6d67d39 - - -] [instance: 2c5a8e62-62d0-430d-8747-795350bb6939] Terminating instance
# df -h
发现磁盘所剩不多了
对策：清理磁盘
疏散失败
执行了个nova疏散命令，疏散不了，nova show 报这个错误：共享存储的状态不对。就是nova instances目录不具备共享存储，如没有配置了ceph共享存储，但是在执行nova evacuate命令的时候还是带了共享存储的参数。
| fault | {"message": "Invalid state of instance files on shared storage", "code": 500, "details": " File \"/usr/lib/python2.7/site-packages/nova/compute/manager.py\", line 354, in decorated_function |
| | return function(self, context, *args, **kwargs) |
| | File \"/usr/lib/python2.7/site-packages/nova/compute/manager.py\", line 3031, in rebuild_instance |
| | _(\"Invalid state of instance files on shared\" |
| | ", "created": "2017-05-17T01:25:17Z"}
有一定的概率无法显示控制台
操作步骤：控制台-虚拟机，点击虚拟机名称，点击【控制台】
预期结果：正常显示console页面
实际结果：有一定概率页面提示“Failed to connect to server”，点击在新窗口打开，可以打开console页面
nova控制节点的配置问题，其配置文件中memcache以及rabbitmq的hosts配置不对
在dashboard界面上，用镜像centos7、flavor–2，创建虚机error。并且抛出的错误是no host，即没有找到合适的调度节点。
若flavor的大小比镜像要求的还小，则会报错。
但又一次出现满足上述条件也报错。
有可能用的flavor被创建不合法的extra_specs
OS-FLV-DISABLED:disabled False
OS-FLV-EXT-DATA:ephemeral 0
disk 20
extra_specs {"xxx": "123", "yyy": "321"}
而过滤选项又开启了ComputeCapabilitiesFilter过滤器。
import error
glance register.log报错：
2017-05-08 03:18:55.890 3185 ERROR glance.common.config [-] Unable to load glance-registry-keystone from configuration file /usr/share/glance/glance-registry-dist-paste.ini.
Got: ImportError('No module named simplegeneric',)
/usr/lib/python2.7/site-packages/simplegeneric.py 没有读权限，被谁给改了
keystone报错
Permission denied: AH00072: make_sock: could not bind to address [::]:5000
[root@controller0 ~]# systemctl start httpd.service
Job for httpd.service failed because the control process exited with error code. See "systemctl status httpd.service" and "journalctl -xe" for details.
[root@controller0 ~]# systemctl status httpd.service
● httpd.service - The Apache HTTP Server
Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Sat 2016-05-28 20:22:34 EDT; 11s ago
Docs: man:httpd(8)
man:apachectl(8)
Process: 4501 ExecStop=/bin/kill -WINCH ${MAINPID} (code=exited, status=1/FAILURE)
Process: 4499 ExecStart=/usr/sbin/httpd $OPTIONS -DFOREGROUND (code=exited, status=1/FAILURE)
Main PID: 4499 (code=exited, status=1/FAILURE)
May 28 20:22:34 controller0 httpd[4499]: (13)Permission denied: AH00072: make_sock: could not bind to address [::]:5000
May 28 20:22:34 controller0 httpd[4499]: (13)Permission denied: AH00072: make_sock: could not bind to address 0.0.0.0:5000
可能是防火墙的配置问题或者selinux
若防火墙没有问题，检查selinux
检查selinux状态
1 [root@controller0 ~]# getenforce
2 enforcing #如果不为disabled 则表示为selinux正常运行
SELINUX=enforcing 改为 selinux=distabled
重启reboot
re-scheduled: Not authorized for image
CLI报错：
| fault | {"message": "Build of instance d5739cf7-9830-47fd-9a75-e9b1cb4bb421 was re-scheduled: Not authorized for image dcd85799-92f6-4294-91ec-48670a218651.", "code": 500, "details": " File \"/usr/lib/python2.7/site-packages/nova/compute/manager.py\", line 2258, in _do_build_and_run_instance |
登陆到该计算节点，也报错
2017-05-18 15:01:24.867 40639 TRACE nova.compute.manager [instance: d5739cf7-9830-47fd-9a75-e9b1cb4bb421] ImageNotAuthorized: Not authorized for image dcd85799-92f6-4294-91ec-48670a218651.
2017-05-18 15:01:24.867 40639 TRACE nova.compute.manager [instance: d5739cf7-9830-47fd-9a75-e9b1cb4bb421]
于是在 /etc/nova/nova.conf中 增加
[DEFAULT]
auth_strategy=keyston
少了个e
应该是:
[DEFAULT]
auth_strategy=keystone
libvirtError: unsupported configuration: IDE controllers are unsupported for this QEMU binary or machine type
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] Traceback (most recent call last):
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2483, in _build_resources
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] yield resources
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 2355, in _build_and_run_instance
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] block_device_info=block_device_info)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 2704, in spawn
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] block_device_info=block_device_info)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 4758, in _create_domain_and_network
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] power_on=power_on)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 4689, in _create_domain
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] LOG.error(err)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 85, in __exit__
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] six.reraise(self.type_, self.value, self.tb)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 4679, in _create_domain
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] domain.createWithFlags(launch_flags)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 186, in doit
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] result = proxy_call(self._autowrap, f, *args, **kwargs)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 144, in proxy_call
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] rv = execute(f, *args, **kwargs)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 125, in execute
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] six.reraise(c, e, tb)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 83, in tworker
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] rv = meth(*args, **kwargs)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] File "/usr/lib64/python2.7/site-packages/libvirt.py", line 1065, in createWithFlags
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] if ret == -1: raise libvirtError ('virDomainCreateWithFlags() failed', dom=self)
2017-05-18 15:06:09.522 41033 TRACE nova.compute.manager [instance: c348b942-4553-4023-bbcb-296f3b1bf14f] libvirtError: unsupported configuration: IDE controllers are unsupported for this QEMU binary or machine type
将IDE改成virtio
qemu-kvm: Cirrus VGA not available
| fault | {"message": "Build of instance a1feb48a-b5f5-48ab-93a7-838bb46573fb was re-scheduled: internal error: process exited while connecting to monitor: 2017-05-18T10:33:34.222333Z qemu-kvm: Cirrus VGA not available", "code": 500, "details": " File \"/usr/lib/python2.7/site-packages/nova/compute/manager.py\", line 2258, in _do_build_and_run_instance |
power架构的机器不支持Cirrus VGA
默认路由不能删除
默认路由怎么也删除不掉
有两个service确认下状态是否正常。network和NetworkManager
dashboard访问卡顿
定位到dashboard卡的原因是应为nova卡，
nova卡顿是因为nova无法与memcached建立连接，
进一步定位到memcached默认的最大连接数是1024，目前已达到最大连接数。
解决办法为编辑 /etc/sysconfig/memcached
参数修改为：
PORT="11211"
USER="memcached"
MAXCONN="65536"
CACHESIZE="1024"
OPTIONS=""
重启memcached
task_state一直处于scheduling
nova boot 执行某一个节点生成vm， task_state一直处于scheduling，vm_state一直处于building，有可能是强制调度的节点的nova-compute state down了。
Access denied for user ‘nova’@’%’ to database ‘nova_api’
初始化nova_api数据库的时候
初始化数据库
su -s /bin/sh -c "nova-manage api_db sync" nova
报错：
Access denied for user 'nova'@'%' to database 'nova_api'
root用户进入数据库，执行
> GRANT ALL PRIVILEGES ON nova_api.* TO 'nova'@'%' IDENTIFIED BY '2267593eb27be7c414fc';
解决
所有节点disk不足，返回0可用host
到该节点df -h发现磁盘空间剩余很多。nova判断节点的磁盘空间不是根据ll判断的，而是根据vm和其他数据一共占用的空间来计算的。
如：
[root@NFJD-PSC-IBMN-SV356 10d31bfa-961d-44ea-b554-7575315a8e2e]# ll -h
total 679M
-rw-rw---- 1 root root 16K Nov 17 17:32 console.log
-rw-r--r-- 1 root root 679M Nov 18 10:07 disk
-rw-r--r-- 1 qemu qemu 422K Nov 17 17:24 disk.config
-rw-r--r-- 1 nova nova 162 Nov 17 17:24 disk.info
-rw-r--r-- 1 nova nova 3.4K Nov 17 17:24 libvirt.xml
[root@NFJD-PSC-IBMN-SV356 10d31bfa-961d-44ea-b554-7575315a8e2e]# qemu-img info disk
image: disk
file format: qcow2
virtual size: 40G (42949672960 bytes)
disk size: 678M
cluster_size: 65536
backing file: /var/lib/nova/instances/_base/af019e4c89c44506c068ada379c040848416510e
Format specific information:
compat: 1.1
lazy refcounts: false
ll 这个文件出来的是600多兆，但是nova统计是按40G来统计的。因为nova代码要统计的是disk_over_committed。nova会把统计的磁盘信息存放在nova数据库的表compute_nodes中提供给调度器。
这里的virtual size减去disk size，便是over_commit_size。
可以看到，这里仅仅对qcow2格式的镜像做了overcommit处理，其它文件的over_commit_size等于0。
在nova调度服务的DiskFilter里面，用到了disk_allocation_ratio对磁盘资源做了超分，它和这里的overcommit不是一个概念，它是从控制节点角度看到的超额使用，而计算节点看不到，overcommit是计算节点看到了磁盘qcow2压缩格式之后所得到的结果，它最终上报的剩余空间是扣除了假设qcow2镜像文件解压之后的实际结果。所以会遇到实际上报的剩余空间小于肉眼看到的空间大小。
如果管理员部署时指定了计算节点，则不走调度流程，就会把虚拟机硬塞给该计算节点，强行占用了已经归入超额分配计划的空间，则最终可能导致计算节点上报的磁盘资源为负数。并且将来随着虚拟机实际占用的磁盘空间越来越大，最终可能就导致计算节点硬盘空间不足了。
novnc打不开问题定位
可能compute的防火墙被改了
在 /etc/sysconfig/iptables 添加
-A INPUT -p tcp --dport 5900:6100 -j ACCEPT
qemu-ga由于找不到对应的虚拟串行字符设备而启动失败，提示找不到channel
glance image-update –property hw_qemu_guest_agent=yes $IMAGE_ID# … 其他属性配置
务必设置property的hw_qemu_guest_agent=yes,否则libvert启动虚拟机时不会生成qemu-ga配置项，导致虚拟机内部的qemu-ga由于找不到对应的虚拟串行字符设备而启动失败，提示找不到channel。
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