问题调查
直接原因
关于Windows虚机激活的问题分析，进行调研后总结如下：Windows 虚机在使用KMS激活方式进行激活时其与KMS Server服务器的时间如果同步则激活成功，但经过我们调查发现，由于云环境中，windows虚机时间与物理机的时间存在偏差，所以导致激活失败。
具体时间偏差
Windows instance 有时候会发现操作系统时间总是慢 8 个小时，即使手工调整好时间和时区，下次 instance 重启后又会差 8 个小时。
为何出现时间偏差呢？
KVM 对 Linux 和 Windows 虚拟机在系统时间上处理有所不同，Windows 需要额外一些设置。
为何Linux 和 Windows 虚拟机在系统时间上处理有所不同呢？要了解下面三个概念。
UTC时间 与 本地时间
UTC时间：又称世界标准时间、世界统一时间，UTC是以原子钟校准的，世界其它地区是以此为基准时间加上自己时区来设置其本地时间的
本地时间：由于处在不同的时区，本地时间一般与UTC是不同的，换算方法就是
本地时间 = UTC + 时区 或 UTC = 本地时间 - 时区
时区东为正，西为负，在中国，时区为东八区，也就是 +8区，本地时间都使用北京时间，在linux上显示就是 CST, 所以CST=UTC+(+8小时) 或 UTC=CST-(+8小时)
guest OS时间保持
kvm技术是全虚拟化，guest OS并不需要做修改就可以直接运行，然而在计时方面却存在问题，guest OS计时的一种方式是通过时钟中断计数，进而换算得到，但host产生的时钟中断不能及时到达所有guest OS，因为guest OS中的中断并不是真正的硬件中断，它是由host注入的中断
许多网络应用，web中的sessions验证等，都会调用系统时间，guest OS中若时间有误，则会引起程序出错，为此，kvm给guest vms提供了一个半虚拟化时钟(kvm-clock),在RHEL5.5及其以上版本中，都使用了kvm-clock作为默认时钟源，可以在guest 中使用下面命令查看是否使用了kvm-clock
cat /sys/devices/system/clocksource/clocksource0/current_clocksource
kvm-clock
在kvm-clock方式下，guest OS不能直接访问Host时钟，Host把系统时间写入一个guest可以读取的内存页，这样guest就可以读取此内存页设置自身硬件时间，但是Host并不是实时更新时间到此内存页，而是在发生一个vm event(vm关机，重启等)时才更新，因此此种方式也不能保持guest时间准确无误
libvirt中设置虚拟机硬件时钟
kvm虚拟机一般使用libvirt进行管理，在虚拟机配置的xml文件中，有关于虚拟机硬件时钟设置项
<clock offset='localtime'>
</clock>
clock的offset属性有”utc”,”localtime”,”timezone”,”variable”四个可选项
如果guest OS是Linux系统，应该选用”utc”，guest OS在启动时便会向host同步一次utc时间，然后根据/etc/localtime中设置的时区，来计算系统时间
如果guest OS是windows系统，则应该选用”localtime”，guest OS在启动时向host同步一次系统时间
openstack云环境下的对策
知道了问题的前因后果，只需要在openstack上加以配置即可。分两类情况，新建的windows虚拟机和存量的windows虚拟机。
对于新建windows虚拟机
就是对已有的windows镜像和以后新建的windows镜像，添加os_type=”windows”信息
[root@build localhost]# glance image-update --property os_type="windows" 1d2afd0f-9162-415c-ace3-97de254b6c9c
1d2afd0f-9162-415c-ace3-97de254b6c9c 是vm id
对于存量的windows虚拟机
要通过暴力修改数据库的办法，具体方案：
（1） 找出要修改的全部的存量windows虚拟机的uuid信息
（2） 进入nova数据库，修改instances表的windows虚拟机的os_type字段，将该字段修改为windows
例如修改windows vm id为f64bf83d-a9f0-4ec5-b481-e3e76e19b6bd 的vm的os_type字段为windows
update instances set os_type=’windows’ where uuid=’ f64bf83d-a9f0-4ec5-b481-e3e76e19b6bd ‘;
（3） 检查os_type字段是否被修改成’windows’
例如select * from instances where uuid=’f64bf83d-a9f0-4ec5-b481-e3e76e19b6bd’;
（4） 硬重启虚机，需提前联系客户
# nova reboot f64bf83d-a9f0-4ec5-b481-e3e76e19b6bd –hard –poll
重启原因：KVM 会获取修改后的数据库信息，更新 XML 配置，保证时间同步。
测试：nova boot生成的vm是否会带有image的keyword
[root@NFJD-TESTVM-CORE-API-1 ~]# glance image-update --property os_type="windows" fb5bc637-c8ab-4999-9e88-da28561fed21
+---------------------+--------------------------------------------------+
| Property | Value |
+---------------------+--------------------------------------------------+
| checksum | 8049db08971bec254be86067025d0c32 |
| container_format | bare |
| created_at | 2016-07-12T06:16:50Z |
| direct_url | sheepdog://fb5bc637-c8ab-4999-9e88-da28561fed21 |
| disk_format | qcow2 |
| hw_qemu_guest_agent | yes |
| id | fb5bc637-c8ab-4999-9e88-da28561fed21 |
| image.os_type | windows |
| min_disk | 0 |
| min_ram | 0 |
| name | Windows-Server-2008-R2-Enterprise-64bit-20160706 |
| os_distro | windows |
| os_type | windows |
| owner | 6c149dcd3cf64171b8dd972dd03bbac0 |
| protected | False |
| size | 10015539200 |
| status | active |
| tags | [] |
| updated_at | 2017-05-05T03:42:50Z |
| virtual_size | None |
| visibility | public |
+---------------------+--------------------------------------------------+
[root@NFJD-TESTVM-CORE-API-1 ~]# nova image-show fb5bc637-c8ab-4999-9e88-da28561fed21
+------------------------------+--------------------------------------------------+
| Property | Value |
+------------------------------+--------------------------------------------------+
| OS-EXT-IMG-SIZE:size | 10015539200 |
| created | 2016-07-12T06:16:50Z |
| id | fb5bc637-c8ab-4999-9e88-da28561fed21 |
| metadata hw_qemu_guest_agent | yes |
| metadata image.os_type | windows |
| metadata os_distro | windows |
| metadata os_type | windows |
| minDisk | 0 |
| minRam | 0 |
| name | Windows-Server-2008-R2-Enterprise-64bit-20160706 |
| progress | 100 |
| status | ACTIVE |
| updated | 2017-05-05T03:42:50Z |
+------------------------------+--------------------------------------------------+
[root@NFJD-TESTVM-CORE-API-1 ~]# nova boot --image fb5bc637-c8ab-4999-9e88-da28561fed21 --flavor 3 --nic net-id=ee98ec6a-e1ed-43eb-9d0a-26080d277484 t4 --availability-zone nova:NFJD-TESTN-COMPUTE-3
+--------------------------------------+-----------------------------------------------------------------------------------------+
| Property | Value |
+--------------------------------------+-----------------------------------------------------------------------------------------+
| OS-DCF:diskConfig | MANUAL |
| OS-EXT-AZ:availability_zone | nova |
| OS-EXT-SRV-ATTR:host | - |
| OS-EXT-SRV-ATTR:hypervisor_hostname | - |
| OS-EXT-SRV-ATTR:instance_name | instance-000056dc |
| OS-EXT-STS:power_state | 0 |
| OS-EXT-STS:task_state | scheduling |
| OS-EXT-STS:vm_state | building |
| OS-SRV-USG:launched_at | - |
| OS-SRV-USG:terminated_at | - |
| accessIPv4 | |
| accessIPv6 | |
| adminPass | DoLL3d65w7cN |
| config_drive | |
| created | 2017-05-05T03:46:42Z |
| flavor | m1.medium (3) |
| hostId | |
| id | f64bf83d-a9f0-4ec5-b481-e3e76e19b6bd |
| image | Windows-Server-2008-R2-Enterprise-64bit-20160706 (fb5bc637-c8ab-4999-9e88-da28561fed21) |
| key_name | - |
| metadata | {} |
| name | t4 |
| os-extended-volumes:volumes_attached | [] |
| progress | 0 |
| security_groups | default |
| status | BUILD |
| tenant_id | 6c149dcd3cf64171b8dd972dd03bbac0 |
| updated | 2017-05-05T03:46:43Z |
| user_id | 62f52135115f4898bd0d82c1f0cd632b |
+--------------------------------------+-----------------------------------------------------------------------------------------+
[root@NFJD-TESTVM-CORE-API-1 ~]# nova show t4
+--------------------------------------+-----------------------------------------------------------------------------------------+
| Property | Value |
+--------------------------------------+-----------------------------------------------------------------------------------------+
| OS-DCF:diskConfig | MANUAL |
| OS-EXT-AZ:availability_zone | nova |
| OS-EXT-SRV-ATTR:host | NFJD-TESTN-COMPUTE-3 |
| OS-EXT-SRV-ATTR:hypervisor_hostname | NFJD-TESTN-COMPUTE-3 |
| OS-EXT-SRV-ATTR:instance_name | instance-000056dc |
| OS-EXT-STS:power_state | 1 |
| OS-EXT-STS:task_state | - |
| OS-EXT-STS:vm_state | active |
| OS-SRV-USG:launched_at | 2017-05-05T03:46:50.000000 |
| OS-SRV-USG:terminated_at | - |
| accessIPv4 | |
| accessIPv6 | |
| config_drive | True |
| created | 2017-05-05T03:46:42Z |
| flavor | m1.medium (3) |
| hostId | c34578f3d9c097be0d91fda237706199673ca7e5a87051f5aad24637 |
| id | f64bf83d-a9f0-4ec5-b481-e3e76e19b6bd |
| image | Windows-Server-2008-R2-Enterprise-64bit-20160706 (fb5bc637-c8ab-4999-9e88-da28561fed21) |
| key_name | - |
| metadata | {} |
| name | t4 |
| net001 network | 192.168.2.92 |
| os-extended-volumes:volumes_attached | [] |
| progress | 0 |
| security_groups | default |
| status | ACTIVE |
| tenant_id | 6c149dcd3cf64171b8dd972dd03bbac0 |
| updated | 2017-05-05T03:46:51Z |
| user_id | 62f52135115f4898bd0d82c1f0cd632b |
+--------------------------------------+-----------------------------------------------------------------------------------------+
MySQL [nova]> select * from instances where uuid='f64bf83d-a9f0-4ec5-b481-e3e76e19b6bd';
+---------------------+---------------------+------------+-------+-------------+----------------------------------+----------------------------------+--------------------------------------+-----------+------------+--------------+----------+----------+-------------+----------+-----------+-------+----------+----------------------+-----------+----------------+--------------+---------------------+---------------+--------------+---------------------+-------------------+--------+---------+----------------------+------------------+---------+--------------------------------------+--------------+------------------+--------------+--------------+--------------+------------+--------------------------+---------------------+----------+------------------+--------------------+-------------------+---------+--------------+-----------+----------------------+---------+-----------+---------+--------------------+
| created_at | updated_at | deleted_at | id | internal_id | user_id | project_id | image_ref | kernel_id | ramdisk_id | launch_index | key_name | key_data | power_state | vm_state | memory_mb | vcpus | hostname | host | user_data | reservation_id | scheduled_at | launched_at | terminated_at | display_name | display_description | availability_zone | locked | os_type | launched_on | instance_type_id | vm_mode | uuid | architecture | root_device_name | access_ip_v4 | access_ip_v6 | config_drive | task_state | default_ephemeral_device | default_swap_device | progress | auto_disk_config | shutdown_terminate | disable_terminate | root_gb | ephemeral_gb | cell_name | node | deleted | locked_by | cleaned | ephemeral_key_uuid |
+---------------------+---------------------+------------+-------+-------------+----------------------------------+----------------------------------+--------------------------------------+-----------+------------+--------------+----------+----------+-------------+----------+-----------+-------+----------+----------------------+-----------+----------------+--------------+---------------------+---------------+--------------+---------------------+-------------------+--------+---------+----------------------+------------------+---------+--------------------------------------+--------------+------------------+--------------+--------------+--------------+------------+--------------------------+---------------------+----------+------------------+--------------------+-------------------+---------+--------------+-----------+----------------------+---------+-----------+---------+--------------------+
| 2017-05-05 03:46:42 | 2017-05-05 03:46:51 | NULL | 22236 | NULL | 62f52135115f4898bd0d82c1f0cd632b | 6c149dcd3cf64171b8dd972dd03bbac0 | fb5bc637-c8ab-4999-9e88-da28561fed21 | | | 0 | NULL | NULL | 1 | active | 4096 | 2 | t4 | NFJD-TESTN-COMPUTE-3 | NULL | r-ae2dhvll | NULL | 2017-05-05 03:46:50 | NULL | t4 | t4 | nova | 0 | windows | NFJD-TESTN-COMPUTE-3 | 3 | NULL | f64bf83d-a9f0-4ec5-b481-e3e76e19b6bd | NULL | /dev/vda | NULL | NULL | True | NULL | NULL | NULL | 0 | 0 | 0 | 0 | 40 | 0 | NULL | NFJD-TESTN-COMPUTE-3 | 0 | NULL | 0 | NULL |
+---------------------+---------------------+------------+-------+-------------+----------------------------------+----------------------------------+--------------------------------------+-----------+------------+--------------+----------+----------+-------------+----------+-----------+-------+----------+----------------------+-----------+----------------+--------------+---------------------+---------------+--------------+---------------------+-------------------+--------+---------+----------------------+------------------+---------+--------------------------------------+--------------+------------------+--------------+--------------+--------------+------------+--------------------------+---------------------+----------+------------------+--------------------+-------------------+---------+--------------+-----------+----------------------+---------+-----------+---------+--------------------+
1 row in set (0.00 sec)
查看到nova数据库里instances表的os_type='windows'
类似的，对于无法获取监控数据的虚机，使用以下办法修改虚机配置：
（1）联系提供镜像的同事确认虚机内已安装qemu-guest-agent
（2）修改nova数据库改虚机字段：
MariaDB [(none)]> use nova;
MariaDB [nova]> insert into instance_system_metadata values(NULL,NULL,NULL,NULL,'2cf79497-d1ba-42c3-adf5-3b45c6927dfb','image_hw_qemu_guest_agent','yes',0);
注： 2cf79497-d1ba-42c3-adf5-3b45c6927dfb 为对应instance的uuid
检查：select * from instance_system_metadata where instance_uuid='3ce9d8b0-a0a3-48ed-ba54-415883f717e5';
（3）再修改虚机所用镜像
# glance image-update xxx --property hw_qemu_guest_agent=yes --property hw_ovirt_guest_agent=yes
（4）硬重启虚机，需提前联系客户
# nova reboot 2cf79497-d1ba-42c3-adf5-3b45c6927dfb --hard --poll
为何修改os_type=’windows’会影响windows虚拟机的时间
openstack会根据os_type的内容来决定提供给底下一层kvm的vm所需的xml内容
通过查询一台windows虚拟机和一台linux虚拟机来对比xml内容，确实windows vm为clock offset=’localtime’ linux vm为clock offset=’utc’
The <clock> element is used to determine how the guest virtual machine clock is synchronized with the host physical machine clock. The clock element has the following attributes:
offset determines how the guest virtual machine clock is offset from the host physical machine clock.
windows虚拟机
[root@NFJD-TESTVM-CORE-API-1 ~]# nova show t4
+--------------------------------------+-----------------------------------------------------------------------------------------+
| Property | Value |
+--------------------------------------+-----------------------------------------------------------------------------------------+
| OS-DCF:diskConfig | MANUAL |
| OS-EXT-AZ:availability_zone | nova |
| OS-EXT-SRV-ATTR:host | NFJD-TESTN-COMPUTE-3 |
| OS-EXT-SRV-ATTR:hypervisor_hostname | NFJD-TESTN-COMPUTE-3 |
| OS-EXT-SRV-ATTR:instance_name | instance-000056dc |
| OS-EXT-STS:power_state | 1 |
| OS-EXT-STS:task_state | - |
| OS-EXT-STS:vm_state | active |
| OS-SRV-USG:launched_at | 2017-05-05T03:46:50.000000 |
| OS-SRV-USG:terminated_at | - |
| accessIPv4 | |
| accessIPv6 | |
| config_drive | True |
| created | 2017-05-05T03:46:42Z |
| flavor | m1.medium (3) |
| hostId | c34578f3d9c097be0d91fda237706199673ca7e5a87051f5aad24637 |
| id | f64bf83d-a9f0-4ec5-b481-e3e76e19b6bd |
| image | Windows-Server-2008-R2-Enterprise-64bit-20160706 (fb5bc637-c8ab-4999-9e88-da28561fed21) |
| key_name | - |
| metadata | {} |
| name | t4 |
| net001 network | 192.168.2.92 |
| os-extended-volumes:volumes_attached | [] |
| progress | 0 |
| security_groups | default |
| status | ACTIVE |
| tenant_id | 6c149dcd3cf64171b8dd972dd03bbac0 |
| updated | 2017-05-05T03:46:51Z |
| user_id | 62f52135115f4898bd0d82c1f0cd632b |
+--------------------------------------+-----------------------------------------------------------------------------------------+
[root@NFJD-TESTN-COMPUTE-3 ~]# virsh dumpxml instance-000056dc
...
<clock offset='localtime'>
<timer name='pit' tickpolicy='delay'/>
<timer name='rtc' tickpolicy='catchup'/>
<timer name='hpet' present='no'/>
</clock>
...
linux虚拟机
[root@NFJD-TESTVM-CORE-API-1 ~]# nova show t1
+--------------------------------------+-------------------------------------------------------------------+
| Property | Value |
+--------------------------------------+-------------------------------------------------------------------+
| OS-DCF:diskConfig | MANUAL |
| OS-EXT-AZ:availability_zone | nova |
| OS-EXT-SRV-ATTR:host | NFJD-TESTN-COMPUTE-1 |
| OS-EXT-SRV-ATTR:hypervisor_hostname | NFJD-TESTN-COMPUTE-1 |
| OS-EXT-SRV-ATTR:instance_name | instance-000056d9 |
| OS-EXT-STS:power_state | 1 |
| OS-EXT-STS:task_state | - |
| OS-EXT-STS:vm_state | active |
| OS-SRV-USG:launched_at | 2017-05-05T02:44:20.000000 |
| OS-SRV-USG:terminated_at | - |
| accessIPv4 | |
| accessIPv6 | |
| config_drive | True |
| created | 2017-05-05T02:44:11Z |
| flavor | m1.medium (3) |
| hostId | f091880caebe68654030e5df4825e49548af0037454e5723961bfc3d |
| id | 6316dc6e-2fb0-4d72-8e99-ad5749efc295 |
| image | CentOS-7.1-x86_64-20161018 (8aaf1759-9fb4-4ba9-8cff-1743eb824c5f) |
| key_name | - |
| metadata | {} |
| name | t1 |
| net001 network | 192.168.2.90 |
| os-extended-volumes:volumes_attached | [] |
| progress | 0 |
| security_groups | default |
| status | ACTIVE |
| tenant_id | 6c149dcd3cf64171b8dd972dd03bbac0 |
| updated | 2017-05-05T03:36:09Z |
| user_id | 62f52135115f4898bd0d82c1f0cd632b |
+--------------------------------------+-------------------------------------------------------------------+
[root@NFJD-TESTN-COMPUTE-1 ~]# virsh dumpxml instance-000056d9
...
<clock offset='utc'>
<timer name='pit' tickpolicy='delay'/>
<timer name='rtc' tickpolicy='catchup'/>
<timer name='hpet' present='no'/>
</clock>
...
分析相关的nova代码
# nova/virt/libvirt/driver.py
def _set_clock(self, guest, os_type, image_meta, virt_type):
# NOTE(mikal): Microsoft Windows expects the clock to be in
# "localtime". If the clock is set to UTC, then you can use a
# registry key to let windows know, but Microsoft says this is
# buggy in http://support.microsoft.com/kb/2687252
clk = vconfig.LibvirtConfigGuestClock()
if os_type == 'windows':
LOG.info(_LI('Configuring timezone for windows instance to '
'localtime'))
clk.offset = 'localtime' # 在os_type为windows的时候clk.offset设置为localtime
else:
clk.offset = 'utc'
guest.set_clock(clk) # 在os_type为linux的时候clk.offset设置为utc
if virt_type == "kvm":
self._set_kvm_timers(clk, os_type, image_meta)转载请注明来源，欢迎指出任何有错误或不够清晰的表达。可以邮件至 backendcloud@gmail.com
