Kvm之九:vm迁移

Centos7 Kvm 虚拟机迁移

1、虚拟机静态迁移

#虚拟机静态迁移两种方式
#1、迁移vm至其他机器上运行，且无共享存储
#2、迁移vm至其他机器上运行，且有共享存储
#迁移vm的思路是将disk img磁盘映像文件与xml配置文件拷贝至目的主机重新定义即可
#环境中部署有共享存储方案，只是需要重新在目标主机定义即可完成vm的迁移
#实验为无共享存储方式

2、准备disk img和xml配置等文件

[root@node71 ~]# virsh list 
 Id    名称                         状态
----------------------------------------------------
 3     oel1                           running

[root@node71 ~]# virsh domblklist oel1
目标     源
------------------------------------------------
vda        /home/data/vm/oel1/oel1_qcow2.img
vdb        /home/data/vm/oel1/oel1_qcow2_1.img

[root@node71 ~]# virsh shutdown oel1
域 oel1 被关闭

[root@node71 ~]# virsh dumpxml oel1 > ./oel1.xml
#scp远程拷贝文件至目标主机
[root@node71 ~]# scp /home/data/vm/oel1/oel1_qcow2.img [email protected]:/data/vm/oel1/
The authenticity of host '192.168.2.110 (192.168.2.110)' can't be established.
ECDSA key fingerprint is ab:ef:f7:83:53:37:da:4d:35:c0:56:0f:9e:bd:01:10.
Are you sure you want to continue connecting (yes/no)? ys
Please type 'yes' or 'no': yes
Warning: Permanently added '192.168.2.110' (ECDSA) to the list of known hosts.
[email protected]'s password: 
oel1_qcow2.img                                             100% 2690MB  41.4MB/s   01:05    
[root@node71 ~]# scp /home/data/vm/oel1/oel1_qcow2_1.img  [email protected]:/data/vm/oel1/
[email protected]'s password: 
oel1_qcow2_1.img                                           100% 1091MB  40.4MB/s   00:27    
[root@node71 ~]# scp ./oel1.xml  [email protected]:/etc/libvirt/qemu/
[email protected]'s password: 
oel1.xml                                                   100% 3089     3.0KB/s   00:00    
[root@node71 ~]# 

3、目标主机将迁移过来的xml配置文件重新注册到kvm

#注册之前，需要确认xml当中配置的disk路径与实际disk 的img文件路径是否一直，
#vi /etc/libvirt/qemu/oel1.xml
  
  
#重新编辑修改正确的disk路径
#目标主机注册迁移虚拟机
[root@node72 ~]# virsh define /etc/libvirt/qemu/oel1.xml
定义域 oel1（从 /etc/libvirt/qemu/oel1.xml）
#启动vm
[root@node72 ~]# virsh start oel1
域 oel1 已开始
#console接入vm
[root@node72 ~]# virsh console oel1
连接到域 oel1
换码符为 ^]

mount: mount point /proc/bus/usb does not exist
        Welcome to Oracle Linux Server
Starting udev: [  OK  ]
Setting hostname localhost.localdomain:  [  OK  ]
Setting up Logical Volume Management:   2 logical volume(s) in volume group "VolGroup" now active
[  OK  ]
Checking filesystems
Checking all file systems.
[/sbin/fsck.ext4 (1) -- /] fsck.ext4 -a /dev/mapper/VolGroup-lv_root 
/dev/mapper/VolGroup-lv_root: clean, 23019/1215840 files, 505899/4859904 blocks
[/sbin/fsck.ext4 (1) -- /boot] fsck.ext4 -a /dev/vda1 
/dev/vda1: clean, 44/128016 files, 81219/512000 blocks
[  OK  ]
Remounting root filesystem in read-write mode:  [  OK  ]
Mounting local filesystems:  [  OK  ]
Enabling /etc/fstab swaps:  [  OK  ]
Entering non-interactive startup
Starting monitoring for VG VolGroup:   2 logical volume(s) in volume group "VolGroup" monitored
[  OK  ]
Bringing up loopback interface:  [  OK  ]
Bringing up interface eth0:  
Determining IP information for eth0... done.
[  OK  ]
Starting auditd: [  OK  ]
Starting system logger: [  OK  ]
Starting kdump:[FAILED]
Mounting filesystems:  [  OK  ]
Starting acpi daemon: [  OK  ]
Retrigger failed udev events[  OK  ]
Starting sshd: [  OK  ]
Starting postfix: [  OK  ]
Starting crond: [  OK  ]

Oracle Linux Server release 6.6
Kernel 3.8.13-44.1.1.el6uek.x86_64 on an x86_64

localhost.localdomain login: root
Password: 
Last login: Tue Oct 25 02:58:14 on ttyS0
[root@localhost ~]# ip a
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 52:54:00:37:5f:f6 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.134/16 brd 192.168.255.255 scope global eth0
    inet6 fe80::5054:ff:fe37:5ff6/64 scope link 
       valid_lft forever preferred_lft forever
#测试网络连通性
[root@localhost ~]# ping -c 2 192.168.0.1
PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data.
64 bytes from 192.168.0.1: icmp_seq=1 ttl=255 time=4.74 ms
64 bytes from 192.168.0.1: icmp_seq=2 ttl=255 time=48.6 ms

--- 192.168.0.1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1063ms
rtt min/avg/max/mdev = 4.744/26.673/48.603/21.930 ms
[root@localhost ~]# 
[root@node72 ~]# 
#检查KVM机器的vnc端口，是否开启，开启则说明可以vnc接入
[root@node72 ~]# ss -tnl
State       Recv-Q Send-Q Local Address:Port                Peer Address:Port              
LISTEN      0      5      192.168.122.1:53                             *:*                  
LISTEN      0      1                  *:5910                           *:*                  
LISTEN      0      128                *:22                             *:*                  
LISTEN      0      128        127.0.0.1:631                            *:*                  
LISTEN      0      100        127.0.0.1:25                             *:*                  
LISTEN      0      128               :::22                            :::*                  
LISTEN      0      128              ::1:631                           :::*                  
LISTEN      0      100              ::1:25                            :::*                  
[root@node72 ~]# 

4、动态迁移

#采用共享存储的方式存放disk img映像文件
#nfs共享存储
[root@node1 ~]# iptables -F
[root@node1 ~]# cat /etc/exports 
/data   *(rw,sync,no_root_squash)
[root@node1 ~]# 
#Kvm节点挂载nfs共享存储，挂载路径一致
[root@node71 ~]# mount -t nfs 192.168.0.211:/data /mnt
[root@node72 ~]# mount -t nfs 192.168.0.211:/data /mnt
#两台KVM检查nfs挂载后vm磁盘文件权限，貌似nobady权限也是可以
[root@node72 ~]# ll -h /mnt/vm/oel2/
总用量 2.0G
-rw-r--r-- 1 nobody nobody 2.0G 10月 26 11:18 oel2_qcow2.img
[root@node72 ~]# 
#有node71运行vm之后，将vm迁移至node72,vm的disk img存放在/mnt/vm/oel1路径下
#检查node71
[root@node71 ~]# virsh domblklist oel2
目标     源
------------------------------------------------
vda        /mnt/vm/oel2/oel2_qcow2.img
hda        -

[root@node71 ~]# virsh list --all
 Id    名称                         状态
----------------------------------------------------
 5     oel2                           running

[root@node71 ~]# 
[root@node71 ~]# ss -tnl
State      Recv-Q Send-Q            Local Address:Port                           Peer Address:Port              
LISTEN     0      5                 192.168.122.1:53                                        *:*                  
LISTEN     0      128                           *:22                                        *:*                  
LISTEN     0      1                             *:5911                                      *:*                  
LISTEN     0      128                   127.0.0.1:631                                       *:*                  
LISTEN     0      100                   127.0.0.1:25                                        *:*                  
LISTEN     0      64                            *:59589                                     *:*                  
LISTEN     0      64                           :::60821                                    :::*                  
LISTEN     0      128                          :::22                                       :::*                  
LISTEN     0      128                         ::1:631                                      :::*                  
LISTEN     0      100                         ::1:25                                       :::*  
[root@node71 ~]# 
#node72检查oel2的disk 文件
#迁移过程中报错，在启动虚拟机时需要关闭cache
[root@node71 ~]# virsh migrate --live oel2 qemu+ssh://192.168.2.110/system
The authenticity of host '192.168.2.110 (192.168.2.110)' can't be established.
ECDSA key fingerprint is ab:ef:f7:83:53:37:da:4d:35:c0:56:0f:9e:bd:01:10.
Are you sure you want to continue connecting (yes/no)? yes
[email protected]'s password: 
错误：不安全的迁移:如果磁盘使用 cache != none 则迁移会导致数据崩溃
错误：无法解析地址 'node72' 服务 '49152': 未知的名称或服务
[root@node71 ~]# 
#这里实验，尝试忽略错误，即使不安全也尝试迁移，并且增加在hosts文件增加名称解析
[root@node71 ~]# cat /etc/hosts
192.168.2.111 node71
192.168.2.110 node72
[root@node71 ~]# 
[root@node71 ~]# virsh migrate --live --verbose --abort-on-error --unsafe  oel2 qemu+ssh://192.168.2.110/system
[email protected]'s password: 
迁移: [100 %]
[root@node71 ~]# virsh list --all
 Id    名称                         状态
----------------------------------------------------
 -     oel2                           关闭
[root@node71 ~]# 
#在node72检查，此时node72上没有oel2的xml配置文件需要重新导出一份（node71上还存在）
[root@node72 ~]# virsh list --all
 Id    名称                         状态
----------------------------------------------------
 3     oel2                           running
[root@node72 ~]# virsh dumpxml oel2 > /etc/libvirt/qemu/oel2.xml
[root@node72 ~]# ls /etc/libvirt/qemu/oel2.xml
/etc/libvirt/qemu/oel2.xml 
[root@node72 ~]# ss -tnl
State      Recv-Q Send-Q            Local Address:Port                           Peer Address:Port              
LISTEN     0      64                            *:40147                                     *:*                  
LISTEN     0      5                 192.168.122.1:53                                        *:*                  
LISTEN     0      128                           *:22                                        *:*                  
LISTEN     0      1                             *:5911                                      *:*                  
LISTEN     0      128                   127.0.0.1:631                                       *:*                  
LISTEN     0      100                   127.0.0.1:25                                        *:*                  
LISTEN     0      128                          :::22                                       :::*                  
LISTEN     0      128                         ::1:631                                      :::*                  
LISTEN     0      100                         ::1:25                                       :::*                  
LISTEN     0      64                           :::42983                                    :::*                  
[root@node72 ~]#
#测试vnc连接无任何问题
#且测试vm网络连通性，一个PING包都不掉

virsh migrate命令帮助

[root@node71 ~]# virsh migrate --help
  NAME
    migrate - 将域迁移到另一个主机中

  SYNOPSIS
    migrate   [--live] [--offline] [--p2p] [--direct] [--tunnelled] [--persistent] [--undefinesource] [--suspend] [--copy-storage-all] [--copy-storage-inc] [--change-protection] [--unsafe] [--verbose] [--compressed] [--auto-converge] [--rdma-pin-all] [--abort-on-error] [--migrateuri ] [--graphicsuri ] [--listen-address ] [--dname ] [--timeout ] [--xml ] [--migrate-disks ]

  DESCRIPTION
    将域迁移到另一个主机中。热迁移时添加 --live。

  OPTIONS
    [--domain]   域名，id 或 uuid
    [--desturi]   客户端（常规迁移）或者源（p2p 迁移）中看到到目的地主机连接 URI
    --live           热迁移
    --offline        离线迁移
    --p2p            点对点迁移
    --direct         直接迁移
    --tunnelled      管道迁移
    --persistent     目的地中的持久 VM
    --undefinesource  在源中取消定义 VM
    --suspend        部启用目的地主机中的域
    --copy-storage-all  使用全磁盘复制的非共享存储进行迁移
    --copy-storage-inc  使用增值复制（源和目的地共享同一基础映像）的非共享存储进行迁移
    --change-protection  迁移结束前不得对域进行任何配置更改
    --unsafe         即使不安全也要强制迁移
    --verbose        显示迁移进程
    --compressed     实时迁移过程中压缩重复的页
    --auto-converge  force convergence during live migration
    --rdma-pin-all   support memory pinning during RDMA live migration
    --abort-on-error  在迁移过程中忽略软错误
    --migrateuri   迁移 URI， 通常可省略
    --graphicsuri   无空隙图形迁移中使用的图形 URI
    --listen-address   listen address that destination should bind to for incoming migration
    --dname   在迁移过长中重新命名为一个新名称（如果支持）
    --timeout   如果 live 迁移超时（以秒计）则强制虚拟机挂起
    --xml    包含为目标更新的 XML 的文件名
    --migrate-disks   comma separated list of disks to be migrated