1. 调整虚拟机

（基本配置就是这样）
image.png
（做虚拟化最主要的就是虚拟引擎的两处勾选）
image.png

2. 检查CPU参数

  1. 启动虚拟机，我们查看以下，内存是否更改成功，命令如下：
  2. [root@kvm ~]# free
  3.        total      used     free      shared    buff/cache   available
  4. Mem:  1868688  125360  1582372     8752     160956     1584208
  5. Swap:  097148     0     2097148
  6. 检查CPU是否开启虚拟化支持，命令如下：
  7. [root@kvm ~]# grep -Ei 'vmx|svm' /proc/cpuinfo
  8. //vmx为英特尔的cpu；svm为AMD的cpu。
  9. flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu pni pclmulqdq vmx ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch arat tpr_shadow vnmi ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 invpcid mpx rdseed adx smap clflushopt xsaveopt xsavec xsaves
  10. flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu pni pclmulqdq vmx ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch arat tpr_shadow vnmi ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 invpcid mpx rdseed adx smap clflushopt xsaveopt xsavec xsaves
  11. 如果显示为空，就要检查你虚拟机设置，是否打“√”

3. 挂载新磁盘

  1. //使用lsblk命令，检查虚拟机是否新增一块50 GB的磁盘，命令如下：
  2. [root@kvm ~]# lsblk
  3. NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
  4. sda               8:0    0   20G  0 disk 
  5. ├─sda1            8:1    0  500M  0 part /boot
  6. └─sda2            8:2    0 19.5G  0 part 
  7.   ├─centos-root 253:0    0 17.5G  0 lvm  /
  8.   └─centos-swap 253:1    0    2G  0 lvm  [SWAP]
  9. sdb               8:16   0   50G  0 disk 
  10. sr0              11:0    1    4G  0 rom 
  11. //我们可以看到确实新增了一块磁盘名为sdb。
  12. //接下来格式化这块磁盘，格式化成ext4格式，命令如下：
  13. [root@kvm ~]# mkfs.ext4 /dev/sdb 
  14. mke2fs 1.42.9 (28-Dec-2013)
  15. /dev/sdb is entire device, not just one partition!
  16. Proceed anyway? (y,n) y
  17. Filesystem label=
  18. OS type: Linux
  19. Block size=4096 (log=2)
  20. Fragment size=4096 (log=2)
  21. Stride=0 blocks, Stripe width=0 blocks
  22. 3276800 inodes, 13107200 blocks
  23. 655360 blocks (5.00%) reserved for the super user
  24. First data block=0
  25. Maximum filesystem blocks=2162163712
  26. 400 block groups
  27. 32768 blocks per group, 32768 fragments per group
  28. 8192 inodes per group
  29. Superblock backups stored on blocks: 
  30. 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
  31. 4096000, 7962624, 11239424
  33. Allocating group tables: done                            
  34. Writing inode tables: done                            
  35. Creating journal (32768 blocks): done
  36. Writing superblocks and filesystem accounting information: done   
  38. [root@kvm ~]# blkid /dev/sdb
  39. //blkid+磁盘：查看磁盘信息
  40. /dev/sdb: UUID="dab6d659-e334-41ed-a15a-96ce05b48c1a" TYPE="ext4" 
  41. 格式化完成后，我们挂载磁盘，先创建挂载目录/kvm_data，然后进行挂载，命令如下：
  42. [root@kvm ~]# mkdir /kvm_data
  43. [root@kvm ~]# mount /dev/sdb /kvm_data/
  44. //这种方式挂载，重启虚拟机后，需要再次重新挂载，我们为了方便开机后可以自动挂载，编写/etc/fstab文件，添加文件最末一行，命令如下：
  45. [root@kvm ~]# vi /etc/fstab 
  46. [root@kvm ~]# cat /etc/fstab 
  48. #
  49. # /etc/fstab
  50. # Created by anaconda on Thu Aug 22 22:51:46 2019
  51. #
  52. # Accessible filesystems, by reference, are maintained under '/dev/disk'
  53. # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
  54. #
  55. /dev/mapper/centos-root /                       xfs     defaults        0 0
  56. UUID=34f3cd91-b7f0-44dd-9334-2bb66e939898 /boot                   xfs     defaults        0 0
  57. /dev/mapper/centos-swap swap                    swap    defaults        0 0
  58. /dev/sdb     /kvm_data           ext4      defaults    0 0

4. 关闭防火墙和selinux

  1. //关闭防火墙并设置开机不自启，命令如下：
  2. [root@kvm ~]# systemctl stop firewalld
  3. [root@kvm ~]# systemctl disable firewalld
  4. Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
  5. Removed symlink /etc/systemd/system/basic.target.wants/firewalld.service.
  6. //关闭SELinux，编辑/etc/selinux/config，将enforcing修改为disabled，命令如下：
  7. [root@kvm ~]# vi /etc/selinux/config
  8. [root@kvm ~]# cat /etc/selinux/config 
  10. # This file controls the state of SELinux on the system.
  11. # SELINUX= can take one of these three values:
  12. #     enforcing - SELinux security policy is enforced.
  13. #     permissive - SELinux prints warnings instead of enforcing.
  14. #     disabled - No SELinux policy is loaded.
  15. SELINUX=disabled 
  16. //修改这一位置的内容
  17. # SELINUXTYPE= can take one of three two values:
  18. #     targeted - Targeted processes are protected,
  19. #     minimum - Modification of targeted policy. Only selected processes are protected. 
  20. #     mls - Multi Level Security protection.
  21. SELINUXTYPE=targeted
  22. //修改完成后，重启虚拟机，使其生效，使用getenforce查看，命令如下：
  23. [root@kvm ~]# getenforce 
  24. Disabled

5. 安装KVM

  1. 上述操作完成后，我们使用Yum进行安装KVM，命令如下：
  2. [root@kvm ~]# yum install -y  virt-*  libvirt  bridge-utils qemu-img
  3. …………
  4. Complete!

正式配置（启动kvm）

1. 配置网卡

  1. //增加桥接网卡ifcfg-br0，命令如下：
  2. [root@kvm ~]# cd /etc/sysconfig/network-scripts/
  3. [root@kvm network-scripts]# cp ifcfg-eno16777736 ifcfg-br0
  4. //ifcfg-eno16777736为配置IP的网卡，你的网卡可能与我的不同
  5. 修改桥接网卡ifcfg-br0的内容，命令如下：
  6. [root@kvm network-scripts]# vi ifcfg-br0 
  7. [root@kvm network-scripts]# cat ifcfg-br0 
  8. TYPE=Bridge
  9. BOOTPROTO=none
  10. NAME=br0
  11. DEVICE=br0
  12. ONBOOT=yes
  13. IPADDR=192.168.16.5
  14. NETMASK=255.255.255.0
  15. GATEWAY=192.168.16.2
  16. DNS1=114.114.114.114
  17. DNS2=8.8.8.8
  18. 修改NAT网卡ifcfg-eno16777736，内容如下：
  19. [root@kvm network-scripts]# vi ifcfg-eno16777736
  20. [root@kvm network-scripts]# cat ifcfg-eno16777736 
  21. TYPE=Ethernet
  22. BOOTPROTO=none
  23. NAME=eno16777736
  24. DEVICE=eno16777736
  25. ONBOOT=yes
  26. BRIDGE=br0
  27. 修改完成网卡内容后，重新启动网卡服务并查看网卡信息，命令如下：
  28. [root@kvm network-scripts]# service network restart
  29. Restarting network (via systemctl):  [  OK  ]     
  30. [root@kvm network-scripts]# ifconfig 
  31. br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
  32.         inet 192.168.16.5  netmask 255.255.255.0  broadcast 
  33. 192.168.16.255
  34.         inet6 fe80::20c:29ff:fe8d:1f90  prefixlen 64  scopeid 0x20<link>
  35.         ether 00:0c:29:8d:1f:90  txqueuelen 0  (Ethernet)
  36.         RX packets 90  bytes 7092 (6.9 KiB)
  37.         RX errors 0  dropped 0  overruns 0  frame 0
  38.         TX packets 38  bytes 3604 (3.5 KiB)
  39.         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
  41. eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  
  42. mtu 1500
  43.         ether 00:0c:29:8d:1f:90  txqueuelen 1000  (Ethernet)
  44.         RX packets 126287  bytes 182444678 (173.9 MiB)
  45.         RX errors 0  dropped 0  overruns 0  frame 0
  46.         TX packets 32532  bytes 2953477 (2.8 MiB)
  47.         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
  49. lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
  50.         inet 127.0.0.1  netmask 255.0.0.0
  51.         inet6 ::1  prefixlen 128  scopeid 0x10<host>
  52.         loop  txqueuelen 0  (Local Loopback)
  53.         RX packets 0  bytes 0 (0.0 B)
  54.         RX errors 0  dropped 0  overruns 0  frame 0
  55.         TX packets 0  bytes 0 (0.0 B)
  56.         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
  57. 可以清楚的看到br0网卡出现并且带有IP，而以前的eno16777736网卡则没有IP。网卡配置完成

2. 启动libvirtd服务

  1. 首先检查KVM模块是否加载，命令如下：    
  2. [root@kvm network-scripts]# lsmod|grep kvm
  3. kvm_intel             162153  0 
  4. kvm                   525259  1 kvm_intel
  5. 启动libvirtd并检查是否成功启动，命令如下：
  6. [root@kvm network-scripts]# systemctl start libvirtd
  7. [root@kvm network-scripts]# ps -ef |grep libvirt
  8. root      17270      1  1 04:36 ?        00:00:00 /usr/sbin/libvirtd
  9. nobody    17383      1  0 04:36 ?        00:00:00 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
  10. root      17384  17383  0 04:36 ?        00:00:00 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/libexec/libvirt_leaseshelper
  11. root      17416   2264  0 04:36 pts/0    00:00:00 grep --color=auto libvirt
  12. 启动成功后，使用brctl命令可以看到两个网卡，如下代码所示：
  13. [root@kvm ~]# cd
  14. [root@kvm ~]# brctl show
  15. bridge name     bridge id               STP enabled     interfaces
  16. br0            8000.000c298d1f90       no          eno16777736
  17. virbr0          8000.525400c7e229       yes           virbr0-nic

3. 命令行安装CentOS 7

我用的是CentOS-7-x86_64-DVD-1511.iso的镜像 通过SCRT上传CentOS 7镜像到/tmp目录下，如果没有镜像的可以自行下载。上传后，使用ll命令查看/tmp目录下是否存在CentOS 7镜像文件，

  1. [root@kvm ~]# ll /tmp/
  2. total 4228096
  3. -rw-r--r--  1 root root 4329570304 Apr 15  2016 CentOS-7-x86_64-DVD-1511.iso
  4. 镜像存在，接下来使用virt-install进行CentOS 7的安装，命令如下：
  5. [root@kvm ~]# virt-install --name=test --memory=512,maxmemory=1024--vcpus=1,maxvcpus=2 --os-type=linux --os-variant=rhel7 --location=/tmp/CentOS-7-x86_64-DVD-1511.iso --disk path=/kvm_data/test.img,size=10 --bridge=br0 --graphics=none --console=pty,target_type=serial  --extra-args="console=tty0 console=ttyS0"

命令解释：
l —name：指定虚拟机的名称。
l —memory：指定分配给虚拟机的内存资源大小。
l maxmemory：指定可调节的最大内存资源大小，因为KVM支持热调整虚拟机的资源。
l —vcpus：指定分配给虚拟机的CPU核心数量。
l maxvcpus：指定可调节的最大CPU核心数量。
l —os-type：指定虚拟机安装的操作系统类型。
l —os-variant：指定系统的发行版本。
l —location：指定ISO镜像文件所在的路径，支持使用网络资源路径，也就是说可以使用URL。
l —disk path：指定虚拟硬盘所存放的路径及名称，size则是指定该硬盘的可用大小，单位是G。
l —bridge：指定使用哪一个桥接网卡，也就是说使用桥接的网络模式。
l —graphics：指定是否开启图形。
l —console：定义终端的属性，target_type 则是定义终端的类型。
l —extra-args：定义终端额外的参数。

  1. 打完上面那条命令后，等一会，就可以看见下面这段命令，这是系统基础设置，带[!]基本都是需要配置的，接下来我们开始配置“Timezone settings”，输入“2”，按Enter键，命令如下：
  2. Starting installer, one moment...
  3. anaconda 21.48.22.56-1 for CentOS 7 started.
  4.  * installation log files are stored in /tmp during the installation
  5.  * shell is available on TTY2
  6.  * when reporting a bug add logs from /tmp as separate text/plain attachments
  7. 17:01:51 Not asking for VNC because we don't have a network
  8. ================================================================================
  9. ================================================================================
  10. Installation
  12.  1) [x] Language settings                 2) [!] Timezone settings
  13.         (English (United States))                (Timezone is not set.)
  14.  3) [!] Installation source               4) [!] Software selection
  15.         (Processing...)                          (Processing...)
  16.  5) [!] Installation Destination          6) [x] Kdump
  17.         (No disks selected)                      (Kdump is enabled)
  18.  7) [ ] Network configuration             8) [!] Root password
  19.         (Not connected)                          (Password is not set.)
  20.  9) [!] User creation
  21.         (No user will be created)
  22.   Please make your choice from above ['q' to quit | 'b' to begin installation | 'r' to refresh]: 2
  23. =====================================================================
  24. “Timezone settings”时区设置选择 5) Asia亚洲，再选择城市 62) Shanghai上海，命令如下：
  25. Timezone settings
  27. Available regions
  28.  1)  Africa                 6)  Atlantic              10)  Pacific
  29.  2)  America                7)  Australia             11)  US
  30.  3)  Antarctica             8)  Europe                12)  Etc
  31.  4)  Arctic                 9)  Indian
  32.  5)  Asia
  33. Please select the timezone.
  34. Use numbers or type names directly [b to region list, q to quit]: 5
  35. ================================================================================
  36. ================================================================================
  37. Timezone settings
  39. Available timezones in region Asia
  40.  1)  Aden                  28)  Irkutsk               54)  Pyongyang
  41.  2)  Almaty                29)  Jakarta               55)  Qatar
  42.  3)  Amman                 30)  Jayapura              56)  Qyzylorda
  43.  4)  Anadyr                31)  Jerusalem             57)  Rangoon
  44.  5)  Aqtau                 32)  Kabul                 58)  Riyadh
  45.  6)  Aqtobe                33)  Kamchatka             59)  Sakhalin
  46.  7)  Ashgabat              34)  Karachi               60)  Samarkand
  47.  8)  Baghdad               35)  Kathmandu             61)  Seoul
  48.  9)  Bahrain               36)  Khandyga              62)  Shanghai
  49. 10)  Baku                  37)  Kolkata               63)  Singapore
  50. 11)  Bangkok             38)Krasnoyarsk             64) Srednekolymsk
  51. 12)  Beirut                39)  Kuala_Lumpur          65)  Taipei
  52. 13)  Bishkek               40)  Kuching               66)  Tashkent
  53. 14)  Brunei                41)  Kuwait                67)  Tbilisi
  54. 15)  Chita                 42)  Macau                 68)  Tehran
  55. 16)  Choibalsan            43)  Magadan               69)  Thimphu
  56. 17)  Colombo               44)  Makassar              70)  Tokyo
  57. 18)  Damascus             45)  Manila                71)  Ulaanbaatar
  58. 19)  Dhaka                 46)  Muscat                72)  Urumqi
  59. 20)  Dili                  47)  Nicosia               73)  Ust-Nera
  60. 21)  Dubai                 48)  Novokuznetsk          74)  Vientiane
  61. 22)  Dushanbe             49)  Novosibirsk           75)  Vladivostok
  62. Press ENTER to continue
  63. 23)  Gaza                  50)  Omsk                  76)  Yakutsk
  64. 24)  Hebron             51)  Oral                  77)  Yekaterinburg
  65. 25)  Ho_Chi_Minh           52)  Phnom_Penh            78)  Yerevan
  66. 26)  Hong_Kong             53)  Pontianak
  67. 27)  Hovd
  68. Please select the timezone.
  69. Use numbers or type names directly [b to region list, q to quit]: 62
  70. ================================================================================
  71. 输入完毕后，可以发现2的[!]变成了[x]，证明配置完毕。
  72. 接下来我们配置“Software selection”，选择“4”，在选择“c”，因为默认就是minimalinstall，按Enter键，命令如下：
  73. Installation
  75.  1) [x] Language settings                 2) [x] Timezone settings
  76.         (English (United States))                (Asia/Shanghai timezone)
  77.  3) [x] Installation source               4) [!] Software selection
  78.         (Local media)                            (Minimal Install)
  79.  5) [!] Installation Destination          6) [x] Kdump
  80.         (No disks selected)                      (Kdump is enabled)
  81.  7) [ ] Network configuration             8) [!] Root password
  82.         (Not connected)                          (Password is not set.)
  83.  9) [!] User creation
  84.         (No user will be created)
  85.   Please make your choice from above ['q' to quit | 'b' to begin installation |
  86.   'r' to refresh]: 4
  87. ================================================================================
  88. ================================================================================
  89. Base environment
  90. Software selection
  92. Base environment
  94.  1)  [x] Minimal Install                 7)  [ ] Server with GUI
  95.  2)  [ ] Compute Node                    8)  [ ] GNOME Desktop
  96.  3)  [ ] Infrastructure Server           9)  [ ] KDE Plasma Workspaces
  97.  4)  [ ] File and Print Server          10)  [ ] Development and Creative Work
  98.  5)  [ ] Basic Web Server station
  99.  6)  [ ] Virtualization Host
  100.   Please make your choice from above ['q' to quit | 'c' to continue |
  101.   'r' to refresh]: c
  102. 接下来我们配置“Installation Destination”，选择“5”，其余的依次选择“c”，按Enter键，命令如下：
  103. Installation
  105.  1) [x] Language settings                 2) [x] Timezone settings
  106.         (English (United States))           (Asia/Shanghai timezone)
  107.  3) [!] Installation source               4) [!] Software selection
  108.         (Processing...)                          (Processing...)
  109.  5) [!] Installation Destination          6) [x] Kdump
  110.         (No disks selected)                      (Kdump is enabled)
  111.  7) [ ] Network configuration             8) [!] Root password
  112.         (Not connected)                          (Password is not set.)
  113.  9) [!] User creation
  114.         (No user will be created)
  115.  Please make your choice from above ['q' to quit | 'b' to begin installation |
  116.  'r' to refresh]: 5
  117. ================================================================================
  118. ================================================================================
  119. Probing storage...
  120. Installation Destination
  122. [x] 1) : 10 GiB (vda)
  124. 1 disk selected; 10 GiB capacity; 10 GiB free ...
  126.   Please make your choice from above ['q' to quit | 'c' to continue |
  127.   'r' to refresh]: c
  128. ================================================================================
  129. ================================================================================
  130. Autopartitioning Options
  132. [ ] 1) Replace Existing Linux system(s)
  134. [x] 2) Use All Space
  136. [ ] 3) Use Free Space
  138. Installation requires partitioning of your hard drive. Select what space to use 
  139. for the install target.
  141.   Please make your choice from above ['q' to quit | 'c' to continue |
  142.   'r' to refresh]: c
  143. ================================================================================
  144. ================================================================================
  145. Partition Scheme Options
  147. [ ] 1) Standard Partition
  149. [ ] 2) Btrfs
  151. [x] 3) LVM
  153. [ ] 4) LVM Thin Provisioning
  155. Select a partition scheme configuration.
  157.   Please make your choice from above ['q' to quit | 'c' to continue |
  158.   'r' to refresh]: c
  159. Generating updated storage configuration
  160. Checking storage configuration...
  161. ================================================================================
  162. ================================================================================
  163. 接下来配置“Root password”，选择8，按Enter键，命令如下：
  164. Installation
  166.  1) [x] Language settings                 2) [x] Timezone settings
  167.         (English (United States))                (Asia/Shanghai timezone)
  168.  3) [x] Installation source               4) [x] Software selection
  169.         (Local media)                            (Minimal Install)
  170.  5) [x] Installation Destination          6) [x] Kdump
  171.         (Automatic partitioning selecte          (Kdump is enabled)
  172.         d)                                8) [!] Root password
  173.  7) [ ] Network configuration                    (Password is not set.)
  174.         (Not connected)
  175.  9) [!] User creation
  176.         (No user will be created)
  177.   Please make your choice from above ['q' to quit | 'b' to begin installation |
  178.   'r' to refresh]: 8
  179. ================================================================================
  180. ================================================================================
  181. Please select new root password. You will have to type it twice.
  182. 依次输入两次密码，密码相同，我设置的为123456，命令如下：
  183. Password: 123456 
  184. //密码为密文，不显示。
  185. Password (confirm): 123456
  186. ================================================================================
  187. ================================================================================
  188. Question
  190. You have provided a weak password: The password fails the dictionary check - it 
  191. is too simplistic/systematic
  192. Would you like to use it anyway?
  193. //这句话的意思：你的密码太过简单，是否使用它，输入yes即可。
  194. Please respond 'yes' or 'no': yes
  195. =========================================================
  196. =========================================================
  197. 配置完成，选择“b”，按Enter键后，开始安装，命令如下：
  198. Installation
  200.  1) [x] Language settings                 2) [x] Timezone settings
  201.         (English (United States))                (Asia/Shanghai timezone)
  202.  3) [x] Installation source               4) [x] Software selection
  203.         (Local media)                            (Minimal Install)
  204.  5) [x] Installation Destination          6) [x] Kdump
  205.         (Automatic partitioning selecte          (Kdump is enabled)
  206.         d)                                8) [x] Root password
  207.  7) [ ] Network configuration                    (Password is set.)
  208.         (Not connected)
  209.  9) [ ] User creation
  210.         (No user will be created)
  211.   Please make your choice from above ['q' to quit | 'b' to begin installation |
  212.   'r' to refresh]: b
  213. ================================================================================
  214. ================================================================================
  215. Progress
  216. Setting up the installation environment
  217. .
  218. Creating disklabel on /dev/vda
  219. .
  220. Creating xfs on /dev/vda1
  221. .
  222. Creating lvmpv on /dev/vda2
  223. .
  224. Creating swap on /dev/mapper/centos-swap
  225. .
  226. ……………………
  227. Installing readline (34/297)
  228. Installing gawk (35/297)
  229. Installing elfutils-libelf (36/297)
  230. Installing libgpg-error (37/297)
  231. Installing libffi (38/297)
  232. Installing libattr (39/297)
  233. Installing libacl (40/297)
  234. Installing libcap (41/297)
  235. Installing libgcrypt (42/297)
  236. Installing cpio (43/297)
  237. Installing libxml2 (44/297)
  238. Installing libnl3 (45/297)
  239. Installing expat (46/297)
  240. Installing p11-kit (47/297)
  241. ……………………
  242. .
  243. Performing post-installation setup tasks
  244. .
  245. Configuring installed system
  246. .
  247. Writing network configuration
  248. .
  249. Creating users
  250. .
  251. Configuring addons
  252. .
  253. Generating initramfs
  254. .
  255. Running post-installation scripts
  256. .
  257.         Use of this product is subject to the license agreement found at /usr/share/centos-release/EULA
  259.         Installation complete.  Press return to quit 
  260. //按回车
  261. ……………………
  262. CentOS Linux 7 (Core)
  263. Kernel 3.10.0-327.el7.x86_64 on an x86_64
  264. localhost login: root
  265. Password: 123456
  266. [root@localhost ~]# 
  267. //按“Ctrl+]”键，退出终端，回到宿主机。
  268. [root@kvm ~]# 
  269. CentOS 7安装完成。

虚拟机管理

1. KVM基本管理

  1. 完成虚拟机安装，已经退回到宿主机，接下来我们来通过宿主机virsh命令进行管理刚才安装的CentOS 7虚拟机。
  2. 查看虚拟机列表，命令如下：
  3. [root@kvm ~]# virsh list
  4. //查看虚拟机列表，只能看到正在运行的虚拟机
  5.  Id    Name                           State
  6. ----------------------------------------------------
  7.  2     test                           running
  8. [root@kvm ~]# virsh list --all
  9. //查看虚拟机列表，包括未运行的虚拟机
  10.  Id    Name                           State
  11. ----------------------------------------------------
  12.  2     test                           running
  13. 进入指定的虚拟，命令如下：
  14. [root@kvm ~]# virsh console test
  15. Connected to domain test
  16. Escape character is ^]
  17. //如果迟迟未动敲下回车就ok，下面就是正常登录时需要输入的用户名密码
  18. CentOS Linux 7 (Core)
  19. Kernel 3.10.0-327.el7.x86_64 on an x86_64
  21. localhost login: 
  22. 若发生以下报错信息，命令如下：
  23. [root@kvm ~]# virsh console test
  24. Connected to domain test
  25. Escape character is ^]
  26. error: operation failed: Active console session exists for this domain
  27. 解决方式，命令如下：
  28. [root@kvm ~]# ps -ef |grep console
  29. root      11167  10987  0 01:55 tty1     00:00:00 virsh console test
  30. root      16017  15750  0 10:01 pts/1    00:00:00 grep --color=auto console
  31. [root@kvm ~]# kill -9 11167
  32. vrish常用命令，命令如下：
  33. virsh shutdown test 
  34. //关闭虚拟机
  35. virsh start test 
  36. //开启虚拟机
  37. virsh destroy test
  38. //类似stop，这个是强制停止
  39. virsh undefine test
  40. //彻底销毁虚拟机，会删除虚拟机配置文件，virsh list --all就看不到
  41. virsh autostart test
  42. //宿主机开机该虚拟机也开机
  43. virsh autostart --disable test
  44. //解除开机启动
  45. virsh suspend test
  46. //挂起
  47. virsh resume test
  48. //恢复

2.克隆虚拟机

  1. 克隆虚拟机之前，要先关闭虚拟机，不然会提示这种错误，命令如下：
  2. [root@kvm ~]# virt-clone --original test --name test02 --file 
  3. /kvm_data/test02.img
  4. ERROR    Domain with devices to clone must be paused or shutoff.
  5. 关闭虚拟机后，再次进行克隆，命令如下：
  6. [root@kvm ~]# virsh shutdown test
  7. Domain test is being shutdown
  8. [root@kvm ~]# virt-clone  --original test --name test02 --file 
  9. /kvm_data/test02.img
  10. Allocating 'test02.img'                        3% 
  11. [=                    ]  20 MB/s | 365 MB  00:08:23 ETA
  12. //开始克隆
  13. [root@kvm ~]# virt-clone  --original test --name test02 --file 
  14. /kvm_data/test02.img
  15. Allocating     'test02.img'         |  10 GB  00:00:35     
  16. Clone 'test02' created successfully.
  17. //克隆完成且成功
  18. 命令解释：
  19.  --original：指定克隆源虚拟机。
  20.  --name：指定克隆后的虚拟机名字。
  21.  --file：指定目标虚拟机的虚拟磁盘文件。
  22. 查看虚拟机配置文件/etc/libvirt/qemu/,看是否增加test02.xml文件，命令如下：
  23. [root@kvm ~]# ls /etc/libvirt/qemu/
  24. networks  test02.xml  test.xml
  25. 接下来，我们启动刚刚克隆的虚拟机test02，首先查看虚拟机列表，然后启动克隆的虚拟机test02，命令如下：
  26. [root@kvm ~]# virsh list --all
  27.  Id    Name                           State
  28. ----------------------------------------------------
  29.  -     test                           shut off
  30.  -     test02                         shut off
  32. [root@kvm ~]# virsh start test02
  33. Domain test02 started

3. 快照管理

  1. //快照是在我们使用Vmware的时候，很常用的一个功能。它可以回到之前的某一状态。在KVM中RAW格式的虚拟磁盘不支持做快照，qcow2支持。
  2. 创建快照，命令如下：
  3. [root@kvm ~]# virsh snapshot-create test
  4. Domain snapshot 1588485687 created
  5. 查看test.img信息，同时会查看到快照列表，命令如下：
  6. [root@kvm ~]# qemu-img info /kvm_data/test.img 
  7. image: /kvm_data/test.img
  8. file format: qcow2
  9. virtual size: 10G (10737418240 bytes)
  10. disk size: 1.1G
  11. cluster_size: 65536
  12. Snapshot list:
  13. ID    TAG       VM SIZE   DATE              VM CLOCK
  14. 1     1588485687    0       2020-05-03 14:01:27   00:00:00.000
  15. Format specific information:
  16.     compat: 1.1
  17. lazy refcounts: true
  18. 列出所有快照，命令如下：
  19. [root@kvm ~]# virsh snapshot-list test
  20.  Name                 Creation Time             State
  21. ------------------------------------------------------------
  22.  1588485687           2020-05-03 14:01:27 +0800 shutoff
  23. 查看当前快照版本，命令如下：
  24. [root@kvm ~]# virsh snapshot-current test
  25. <domainsnapshot>
  26.   <name>1588485687</name>
  27.   <state>shutoff</state>
  28.   <creationTime>1588485687</creationTime>
  29.   <memory snapshot='no'/>
  30.   <disks>
  31.     <disk name='vda' snapshot='internal'/>
  32.     <disk name='hda' snapshot='no'/>
  33.   </disks>
  34.   <domain type='kvm'>
  35.     <name>test</name>
  36.     <uuid>49d7cb9c-20dc-42dd-a260-01532b5132e5</uuid>
  37.     <memory unit='KiB'>1048576</memory>
  38.     <currentMemory unit='KiB'>524288</currentMemory>
  39.     <vcpu placement='static' current='1'>2</vcpu>
  40.     <os>
  41.       <type arch='x86_64' machine='pc-i440fx-rhel7.0.0'>hvm</type>
  42.       <boot dev='hd'/>
  43.     </os>
  44.     <features>
  45.       <acpi/>
  46.       <apic/>
  47.     </features>
  48.     <cpu mode='custom' match='exact' check='partial'>
  49.       <model fallback='allow'>Broadwell-noTSX-IBRS</model>
  50.       <feature policy='require' name='md-clear'/>
  51.       <feature policy='require' name='spec-ctrl'/>
  52.       <feature policy='require' name='ssbd'/>
  53.     </cpu>
  54.     <clock offset='utc'>
  55.       <timer name='rtc' tickpolicy='catchup'/>
  56.       <timer name='pit' tickpolicy='delay'/>
  57.       <timer name='hpet' present='no'/>
  58.     </clock>
  59.     <on_poweroff>destroy</on_poweroff>
  60.     <on_reboot>restart</on_reboot>
  61.     <on_crash>destroy</on_crash>
  62.     <pm>
  63.       <suspend-to-mem enabled='no'/>
  64.       <suspend-to-disk enabled='no'/>
  65.     </pm>
  66.     <devices>
  67.       <emulator>/usr/libexec/qemu-kvm</emulator>
  68.       <disk type='file' device='disk'>
  69.         <driver name='qemu' type='qcow2'/>
  70.         <source file='/kvm_data/test.img'/>
  71.         <target dev='vda' bus='virtio'/>
  72.         <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
  73.       </disk>
  74.       <disk type='file' device='cdrom'>
  75.         <driver name='qemu' type='raw'/>
  76.         <target dev='hda' bus='ide'/>
  77.         <readonly/>
  78.         <address type='drive' controller='0' bus='0' target='0' unit='0'/>
  79.       </disk>
  80.       <controller type='usb' index='0' model='ich9-ehci1'>
  81.         <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x7'/>
  82.       </controller>
  83.       <controller type='usb' index='0' model='ich9-uhci1'>
  84.         <master startport='0'/>
  85.         <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0' multifunction='on'/>
  86.       </controller>
  87.       <controller type='usb' index='0' model='ich9-uhci2'>
  88.         <master startport='2'/>
  89.         <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x1'/>
  90.       </controller>
  91.       <controller type='usb' index='0' model='ich9-uhci3'>
  92.         <master startport='4'/>
  93.         <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x2'/>
  94.       </controller>
  95.       <controller type='ide' index='0'>
  96.         <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
  97.       </controller>
  98.       <controller type='virtio-serial' index='0'>
  99.         <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
  100.       </controller>
  101.       <controller type='pci' index='0' model='pci-root'/>
  102.       <interface type='bridge'>
  103.         <mac address='52:54:00:93:bf:07'/>
  104.         <source bridge='br0'/>
  105.         <model type='virtio'/>
  106.         <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
  107.       </interface>
  108.       <serial type='pty'>
  109.         <target type='isa-serial' port='0'>
  110.           <model name='isa-serial'/>
  111.         </target>
  112.       </serial>
  113.       <console type='pty'>
  114.         <target type='serial' port='0'/>
  115.       </console>
  116.       <channel type='unix'>
  117.         <target type='virtio' name='org.qemu.guest_agent.0'/>
  118.         <address type='virtio-serial' controller='0' bus='0' port='1'/>
  119.       </channel>
  120.       <input type='mouse' bus='ps2'/>
  121.       <input type='keyboard' bus='ps2'/>
  122.       <memballoon model='virtio'>
  123.         <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
  124.       </memballoon>
  125.       <rng model='virtio'>
  126.         <backend model='random'>/dev/urandom</backend>
  127.         <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
  128.       </rng>
  129.     </devices>
  130.   </domain>
  131. </domainsnapshot>
  132. 查看所有快照配置文件，命令如下：
  133. [root@kvm ~]# ls /var/lib/libvirt/qemu/snapshot/test/
  134. 1588485687.xml
  135. 恢复指定快照，命令如下：
  136. [root@kvm ~]# virsh snapshot-revert test 1588485687
  137. 删除指定快照，命令如下：
  138. [root@kvm ~]# virsh snapshot-delete test 1588485687
  139. Domain snapshot 1588485687 deleted

4. 磁盘格式

  1. 查看虚拟磁盘格式，命令如下：
  2. [root@kvm ~]# qemu-img info /kvm_data/test.img
  3. image: /kvm_data/test.img
  4. file format: qcow2
  5. virtual size: 10G (10737418240 bytes)
  6. disk size: 1.1G
  7. cluster_size: 65536
  8. Format specific information:
  9.     compat: 1.1
  10. lazy refcounts: true
  11. 创建2 GB的RAW格式磁盘，命令如下：
  12. [root@kvm ~]# qemu-img create -f raw /kvm_data/test_1.img 2G
  13. Formatting '/kvm_data/test_1.img', fmt=raw size=2147483648 
  14. RAW格式的磁盘转换为qcow2格式，命令如下：
  15. [root@kvm ~]# qemu-img convert -O qcow2 /kvm_data/test_1.img 
  16. /kvm_data/test_1.qcow2
  17. 查看test1.img大小，命令如下：
  18. [root@kvm ~]# ls -lh /kvm_data/test_1.img 
  19. -rw-r--r-- 1 root root 2.0G May  3 15:11 /kvm_data/test_1.img
  20. [root@kvm ~]# ls -lh /kvm_data/test_1.qcow2 
  21. -rw-r--r-- 1 root root 193K May  3 15:38 /kvm_data/test_1.qcow2
  22. //可以看到qcow2文件比较小，raw文件大小和我们指定空间大小一样是2G
  23. //raw格式的磁盘性能比qcow2要好，但是raw格式的磁盘无法做快照
  24. 将test02转成raw格式，命令如下：
  25. [root@kvm ~]# qemu-img convert -O raw 
  26. /kvm_data/test02.img  /kvm_data/test02_2.raw
  27. 更改磁盘格式和文件路径，然后启动test02虚拟机，命令如下：
  28. [root@kvm ~]# virsh edit test02
  29. …………
  30. <disk type='file' device='disk'>
  31.       <driver name='qemu' type='qcow'/>
  32.       <source file='/kvm_data/test02.img'/>
  33.       <target dev='vda' bus='virtio'/>
  34.       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
  35. </disk>
  36. //找到上面这部分将qcow修改为raw，/kvm_data/test02.img改为/kvm_data/test02_2.raw
  37. <disk type='file' device='disk'>
  38.       <driver name='qemu' type='raw'/>
  39.       <source file='/kvm_data/test02_2.raw'/>
  40.       <target dev='vda' bus='virtio'/>
  41.       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
  42. </disk>
  43. ………………
  44. 查看磁盘所属用户和组，命令如下：
  45. [root@kvm ~]# ls -l /kvm_data/
  46. total 3310628
  47. drwx------ 2 root root       16384 Apr 29 00:20 lost+found
  48. -rw-r--r-- 1 root root 10737418240 May  3 16:14 test02_2.raw
  49. -rw------- 1 root root  1133772800 May  3 16:02 test02.img
  50. -rw-r--r-- 1 root root  2147483648 May  3 15:11 test_1.img
  51. -rw-r--r-- 1 root root      197120 May  3 16:05 test_1.qcow2
  52. -rw------- 1 root root 10739384832 May  3 14:14 test.img
  53. 启动虚拟机test02，然后再次查看磁盘所属用户和组，命令如下：    
  54. [root@kvm ~]# virsh start test02
  55. Domain test02 started
  56. [root@kvm ~]# ls -l /kvm_data/
  57. total 3310628
  58. drwx------ 2 root root       16384 Apr 29 00:20 lost+found
  59. -rw-r--r-- 1 qemu qemu 10737418240 May  3 16:14 test02_2.raw
  60. -rw------- 1 root root  1133772800 May  3 16:02 test02.img
  61. -rw-r--r-- 1 root root  2147483648 May  3 15:11 test_1.img
  62. -rw-r--r-- 1 root root      197120 May  3 16:05 test_1.qcow2
  63. -rw------- 1 root root 10739384832 May  3 14:14 test.img
  64. //启动后所属组变化成qemu的是test02_2.raw，证明这个磁盘正在被使用

5. 磁盘扩容

  1. 我们知道，在这里磁盘一共有两种格式，一种是RAW格式，一种是qcow2格式，接下来我们分别给这两种磁盘格式进行扩容。
  2. 首先扩容RAW格式，命令如下：
  3. [root@kvm ~]# qemu-img resize /kvm_data/test02_2.raw +2G
  4. Image resized.
  5. 查看test02_2.raw信息，命令如下：
  6. [root@kvm ~]# qemu-img info /kvm_data/test02_2.raw 
  7. image: /kvm_data/test02_2.raw
  8. file format: raw
  9. virtual size: 12G (12884901888 bytes)
  10. disk size: 1.0G
  11. 进入虚拟机test02，使用fdisk -l查看磁盘，命令如下：
  12. [root@kvm ~]# virsh console test02
  13. [root@localhost ~]# fdisk -l
  14. Disk /dev/vda: 10.7 GB, 10737418240 bytes, 20971520 sectors
  15. Units = sectors of 1 * 512 = 512 bytes
  16. Sector size (logical/physical): 512 bytes / 512 bytes
  17. I/O size (minimum/optimal): 512 bytes / 512 bytes
  18. Disk label type: dos
  19. Disk identifier: 0x0005b865
  20. Device Boot      Start         End      Blocks   Id  System
  21. /dev/vda1   *        2048     1026047      512000   83  Linux
  22. /dev/vda2         1026048    20971519     9972736   8e  Linux LVM
  24. Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
  25. Units = sectors of 1 * 512 = 512 bytes
  26. Sector size (logical/physical): 512 bytes / 512 bytes
  27. I/O size (minimum/optimal): 512 bytes / 512 bytes
  29. Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
  30. Units = sectors of 1 * 512 = 512 bytes
  31. Sector size (logical/physical): 512 bytes / 512 bytes
  32. I/O size (minimum/optimal): 512 bytes / 512 bytes
  33. //可以看到磁盘还是10 GB
  34. 退出终端，关闭test02虚拟机，重新启动，然后再次进入虚拟机test02，使用fdisk -l查看磁盘，命令如下：
  35. [root@kvm ~]# virsh destroy test02
  36. Domain test02 destroyed
  38. [root@kvm ~]# virsh start test02
  39. Domain test02 started
  41. [root@kvm ~]# virsh console test02
  42. [root@localhost ~]# fdisk -l
  43. Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
  44. Units = sectors of 1 * 512 = 512 bytes
  45. Sector size (logical/physical): 512 bytes / 512 bytes
  46. I/O size (minimum/optimal): 512 bytes / 512 bytes
  47. Disk label type: dos
  48. Disk identifier: 0x0005b865
  49. Device Boot       Start       End          Blocks   Id  System
  50. /dev/vda1   *     2048       1026047      512000   83  Linux
  51. /dev/vda2         1026048    20971519     9972736  8e  Linux LVM
  53. Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
  54. Units = sectors of 1 * 512 = 512 bytes
  55. Sector size (logical/physical): 512 bytes / 512 bytes
  56. I/O size (minimum/optimal): 512 bytes / 512 bytes
  59. Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
  60. Units = sectors of 1 * 512 = 512 bytes
  61. Sector size (logical/physical): 512 bytes / 512 bytes
  62. I/O size (minimum/optimal): 512 bytes / 512 bytes
  63. 可以看到已经变成12 GB了。
  64. 接下来，我们怎么使用新增加的这2 GB磁盘，那就是分区，命令如下：
  65. [root@localhost ~]# fdisk /dev/vda
  66. Welcome to fdisk (util-linux 2.23.2).
  68. Changes will remain in memory only, until you decide to write them.
  69. Be careful before using the write command.
  71. Command (m for help): n
  72. //新建分区
  73. Partition type:
  74.    p   primary (2 primary, 0 extended, 2 free)
  75.    e   extended
  76. Select (default p): p
  77. Partition number (3,4, default 3):
  78. //按Enter键 
  79. First sector (20971520-25165823, default 20971520): 
  80. //按Enter键 
  81. Using default value 20971520
  82. Last sector, +sectors or +size{K,M,G} (20971520-25165823, default 25165823):
  83. //按Enter键
  84. Using default value 25165823
  85. Partition 3 of type Linux and of size 2 GiB is set
  86. Command (m for help): p
  87. //查看分区列表
  88. Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
  89. Units = sectors of 1 * 512 = 512 bytes
  90. Sector size (logical/physical): 512 bytes / 512 bytes
  91. I/O size (minimum/optimal): 512 bytes / 512 bytes
  92. Disk label type: dos
  93. Disk identifier: 0x0005b865
  95. Device Boot      Start       End          Blocks   Id  System
  96. /dev/vda1   *    2048       1026047      512000   83  Linux
  97. /dev/vda2        1026048    20971519     9972736  8e  Linux LVM
  98. /dev/vda3        20971520   25165823     2097152  83  Linux
  100. Command (m for help): w
  101. //保存退出并退出终端
  102. 除了对已有磁盘扩容外，还可以额外增加磁盘，命令如下：
  103. [root@kvm ~]# qemu-img create -f raw /kvm_data/test02_3.raw 5G
  104. Formatting '/kvm_data/test02_3.raw', fmt=raw size=5368709120 
  105. 使用virsh edit编辑test02虚拟机，将新磁盘增加到test02虚拟机，命令如下
  106. [root@kvm ~]# virsh edit test02
  107. ………………
  108.     <disk type='file' device='disk'>
  109.       <driver name='qemu' type='raw'/>
  110.       <source file='/kvm_data/test02_2.raw'/>
  111.       <target dev='vda' bus='virtio'/>
  112.       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' 
  113. function='0x0'/>
  114. </disk>
  115. //找到这一部分内容，在下面增加以下内容
  116.     <disk type='file' device='disk'>
  117.       <driver name='qemu' type='raw'/>
  118.       <source file='/kvm_data/test02_3.raw'/>
  119.       <target dev='vdb' bus='virtio'/>
  120.       <address type='pci' domain='0x0000' bus='0x00' slot='0x09' 
  121. function='0x0'/>
  122. </disk>
  123. ………………
  125. 关闭test02虚拟机，重新启动，然后进入该虚拟机，使用fdisk -l查看磁盘，命令如下：
  126. [root@kvm ~]# virsh destroy test02
  127. Domain test02 destroyed
  129. [root@kvm ~]# virsh start test02
  130. Domain test02 started
  131. [root@kvm ~]# virsh console test02
  132. [root@localhost ~]# fdisk -l
  134. Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
  135. Units = sectors of 1 * 512 = 512 bytes
  136. Sector size (logical/physical): 512 bytes / 512 bytes
  137. I/O size (minimum/optimal): 512 bytes / 512 bytes
  138. Disk label type: dos
  139. Disk identifier: 0x0005b865
  141.    Device Boot      Start      End         Blocks   Id  System
  142. /dev/vda1   *        2048     1026047     512000   83  Linux
  143. /dev/vda2         1026048    20971519     9972736   8e  Linux LVM
  144. /dev/vda3        20971520    25165823     2097152   83  Linux
  146. Disk /dev/vdb: 5368 MB, 5368709120 bytes, 10485760 sectors
  147. Units = sectors of 1 * 512 = 512 bytes
  148. Sector size (logical/physical): 512 bytes / 512 bytes
  149. I/O size (minimum/optimal): 512 bytes / 512 bytes
  152. Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
  153. Units = sectors of 1 * 512 = 512 bytes
  154. Sector size (logical/physical): 512 bytes / 512 bytes
  155. I/O size (minimum/optimal): 512 bytes / 512 bytes
  158. Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
  159. Units = sectors of 1 * 512 = 512 bytes
  160. Sector size (logical/physical): 512 bytes / 512 bytes
  161. I/O size (minimum/optimal): 512 bytes / 512 bytes
  162. 可以看到多了一块5 GB的磁盘，退出终端。
  163. 接下来，我们扩容qcow2格式的磁盘，命令如下：
  164. [root@kvm ~]# qemu-img resize /kvm_data/test.img +2G
  165. Image resized.
  166. //若提示qemu-img: Can't resize an image which has snapshots，需要删除快照
  167. 查看test.img信息，命令如下：
  168. [root@kvm ~]# qemu-img info /kvm_data/test.img 
  169. image: /kvm_data/test.img
  170. file format: qcow2
  171. virtual size: 12G (12884901888 bytes)
  172. disk size: 1.1G
  173. cluster_size: 65536
  174. Format specific information:
  175.     compat: 1.1
  176. lazy refcounts: true
  177. 关闭test虚拟机，重新启动，然后再次进入虚拟机test02，使用fdisk -l查看磁盘，命令如下：
  178. [root@kvm ~]# virsh destroy test
  179. Domain test destroyed
  181. [root@kvm ~]# virsh start test
  182. Domain test started
  184. [root@kvm ~]# virsh console test
  185. [root@localhost ~]# fdisk -l
  186. Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
  187. Units = sectors of 1 * 512 = 512 bytes
  188. Sector size (logical/physical): 512 bytes / 512 bytes
  189. I/O size (minimum/optimal): 512 bytes / 512 bytes
  190. Disk label type: dos
  191. Disk identifier: 0x0005b865
  193. Device Boot      Start      End          Blocks   Id  System
  194. /dev/vda1   *     2048     1026047      512000   83  Linux
  195. /dev/vda2         1026048  20971519     9972736  8e  Linux LVM
  197. Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
  198. Units = sectors of 1 * 512 = 512 bytes
  199. Sector size (logical/physical): 512 bytes / 512 bytes
  200. I/O size (minimum/optimal): 512 bytes / 512 bytes
  203. Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
  204. Units = sectors of 1 * 512 = 512 bytes
  205. Sector size (logical/physical): 512 bytes / 512 bytes
  206. I/O size (minimum/optimal): 512 bytes / 512 bytes
  207. 分区新增加的2 GB磁盘，命令如下：
  208. [root@localhost ~]# fdisk /dev/vda
  209. Welcome to fdisk (util-linux 2.23.2).
  211. Changes will remain in memory only, until you decide to write them.
  212. Be careful before using the write command.
  215. Command (m for help): n
  216. Partition type:
  217.    p   primary (2 primary, 0 extended, 2 free)
  218.    e   extended
  219. Select (default p): p
  220. Partition number (3,4, default 3): 
  221. First sector (20971520-25165823, default 20971520): 
  222. Using default value 20971520
  223. Last sector, +sectors or +size{K,M,G} (20971520-25165823, default 25165823): 
  224. Using default value 25165823
  225. Partition 3 of type Linux and of size 2 GiB is set
  227. Command (m for help): w
  228. /保存并退出终端
  229. 新增一块qcow2格式的磁盘，命令如下：
  230. [root@kvm ~]# qemu-img create -f qcow2 /kvm_data/test_2.img 5G
  231. Formatting '/kvm_data/test_2.img', fmt=qcow2 size=5368709120 encryption=off cluster_size=65536 lazy_refcounts=off
  232. 使用virsh edit编辑test虚拟机，将新磁盘增加到test虚拟机，命令如下：
  233. [root@kvm ~]# virsh edit test
  234. ………………
  235.     <disk type='file' device='disk'>
  236.       <driver name='qemu' type='qcow2'/>
  237.       <source file='/kvm_data/test.img'/>
  238.       <target dev='vda' bus='virtio'/>
  239.       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
  240. </disk>
  241. //找到这一部分内容，在下面增加以下内容
  242.        <disk type='file' device='disk'>
  243.       <driver name='qemu' type='qcow2'/>
  244.       <source file='/kvm_data/test_2.img'/>
  245.       <target dev='vdb' bus='virtio'/>
  246.       <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
  247. </disk>
  248. ………………
  249. 关闭test虚拟机，重新启动，然后进入该虚拟机，使用fdisk -l查看磁盘，命令如下：
  250. [root@kvm ~]# virsh destroy test
  251. Domain test destroyed
  253. [root@kvm ~]# virsh start test
  254. Domain test started
  256. [root@kvm ~]# virsh console test
  257. [root@localhost ~]# fdisk -l
  259. Disk /dev/vda: 12.9 GB, 12884901888 bytes, 25165824 sectors
  260. Units = sectors of 1 * 512 = 512 bytes
  261. Sector size (logical/physical): 512 bytes / 512 bytes
  262. I/O size (minimum/optimal): 512 bytes / 512 bytes
  263. Disk label type: dos
  264. Disk identifier: 0x0005b865
  266. Device Boot      Start       End          Blocks   Id  System
  267. /dev/vda1   *    2048       1026047      512000    83  Linux
  268. /dev/vda2        1026048    20971519     9972736   8e  Linux LVM
  269. /dev/vda3        20971520   25165823     2097152   83  Linux
  271. Disk /dev/vdb: 5368 MB, 5368709120 bytes, 10485760 sectors
  272. Units = sectors of 1 * 512 = 512 bytes
  273. Sector size (logical/physical): 512 bytes / 512 bytes
  274. I/O size (minimum/optimal): 512 bytes / 512 bytes
  276. Disk /dev/mapper/centos-root: 9093 MB, 9093251072 bytes, 17760256 sectors
  277. Units = sectors of 1 * 512 = 512 bytes
  278. Sector size (logical/physical): 512 bytes / 512 bytes
  279. I/O size (minimum/optimal): 512 bytes / 512 bytes
  281. Disk /dev/mapper/centos-swap: 1073 MB, 1073741824 bytes, 2097152 sectors
  282. Units = sectors of 1 * 512 = 512 bytes
  283. Sector size (logical/physical): 512 bytes / 512 bytes
  284. I/O size (minimum/optimal): 512 bytes / 512 bytes
  285. 退出终端

6. 调整CPU内存、网卡

  1. 查看虚拟机配置信息，命令如下：
  2. [root@kvm ~]# virsh dominfo test
  3. Id:             8
  4. Name:           test
  5. UUID:           49d7cb9c-20dc-42dd-a260-01532b5132e5
  6. OS Type:        hvm
  7. State:          running
  8. CPU(s):         1
  9. CPU time:       20.8s
  10. Max memory:     1048576 KiB
  11. Used memory:    524288 KiB
  12. Persistent:     yes
  13. Autostart:      disable
  14. Managed save:   no
  15. Security model: none
  16. Security DOI:   0
  17. 编辑虚拟机内存，命令如下：
  18. [root@kvm ~]# virsh edit test
  19. …………
  20. <memory unit='KiB'>1048576</memory>
  21. //最大内存
  22.   <currentMemory unit='KiB'>524288</currentMemory>
  23. //可用内存
  24.   <vcpu placement='static' current='1'>2</vcpu>
  25. //最大cpu
  26. ………………
  27. //将以上内容修改为如下内容
  28. …………
  29. <memory unit='KiB'>1048576</memory>  
  30.   <currentMemory unit='KiB'>624288</currentMemory>
  31.   <vcpu placement='static' current='1'>2</vcpu>
  32. …………
  33. 关闭虚拟机，重启动虚拟机，命令如下：
  34. [root@kvm ~]# virsh destroy test
  35. Domain test destroyed
  36. [root@kvm ~]# virsh start test
  37. Domain test started
  38. 查看虚拟机配置信息，看是否修改成功，命令如下：
  39. [root@kvm ~]# virsh dominfo test
  40. Id:             10
  41. Name:           test
  42. UUID:           49d7cb9c-20dc-42dd-a260-01532b5132e5
  43. OS Type:        hvm
  44. State:          running
  45. CPU(s):         1
  46. CPU time:       21.4s
  47. Max memory:     1048576 KiB
  48. Used memory:    624288 KiB
  49. Persistent:     yes
  50. Autostart:      disable
  51. Managed save:   no
  52. Security model: none
  53. Security DOI:   0
  54. 除了这种修改方式之外，还有一种动态修改，命令如下：
  55. [root@kvm ~]# virsh setmem test 800m
  56. //动态修改内存
  57. [root@kvm ~]# virsh setvcpus test 2
  58. //动态修改cpu，只可以增加不可以减少
  59. 查看配置信息，看是否修改成功，命令如下：
  60. [root@kvm ~]# virsh dominfo test
  61. Id:             10
  62. Name:           test
  63. UUID:           49d7cb9c-20dc-42dd-a260-01532b5132e5
  64. OS Type:        hvm
  65. State:          running
  66. CPU(s):         2
  67. CPU time:       22.8s
  68. Max memory:     1048576 KiB
  69. Used memory:    819200 KiB
  70. Persistent:     yes
  71. Autostart:      disable
  72. Managed save:   no
  73. Security model: none
  74. Security DOI:   0
  76. [root@kvm ~]# virsh dumpxml test > /etc/libvirt/qemu/test.xml
  77. //需要把配置写入到配置文件里
  78. 查看网卡列表，命令如下：
  79. [root@kvm ~]# virsh domiflist test
  80. Interface  Type       Source     Model       MAC
  81. -------------------------------------------------------
  82. vnet1      bridge     br0        virtio      52:54:00:93:bf:07
  83. 增加一块新的网卡，并设置为NAT网络模式（virbr0类似VMware的VMnet8），这里如果写--source br0，则网络模式为桥接，命令如下：
  84. [root@kvm ~]# virsh attach-interface test --type bridge  --source virbr0
  85. Interface attached successfully
  86. [root@kvm ~]# virsh domiflist test
  87. Interface  Type       Source     Model       MAC
  88. -------------------------------------------------------
  89. vnet1      bridge     br0        virtio      52:54:00:93:bf:07
  90. vnet2      bridge     virbr0     rtl8139     52:54:00:29:ed:8b
  91. [root@kvm ~]# virsh dumpxml test > /etc/libvirt/qemu/test.xml
  92. 进入test虚拟机，查看网卡信息，命令如下：
  93. [root@kvm ~]# virsh console test
  94. [root@localhost ~]# ifconfig
  95. ens10: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
  96.         inet 192.168.122.8  netmask 255.255.255.0  broadcast 192.168.122.255
  97.         inet6 fe80::5054:ff:fe29:ed8b  prefixlen 64  scopeid 0x20<link>
  98.         ether 52:54:00:29:ed:8b  txqueuelen 1000  (Ethernet)
  99.         RX packets 5186  bytes 7413267 (7.0 MiB)
  100.         RX errors 0  dropped 0  overruns 0  frame 0
  101.         TX packets 1480  bytes 84889 (82.8 KiB)
  102.         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
  104. ens11: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
  105.         inet 192.168.16.129  netmask 255.255.255.0  broadcast 192.168.16.255
  106.         inet6 fe80::5054:ff:fe15:abbd  prefixlen 64  scopeid 0x20<link>
  107.         ether 52:54:00:15:ab:bd  txqueuelen 1000  (Ethernet)
  108.         RX packets 13  bytes 1328 (1.2 KiB)
  109.         RX errors 0  dropped 0  overruns 0  frame 0
  110.         TX packets 16  bytes 1668 (1.6 KiB)
  111.         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
  113. eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
  114.         ether 52:54:00:93:bf:07  txqueuelen 1000  (Ethernet)
  115.         RX packets 55  bytes 8520 (8.3 KiB)
  116.         RX errors 0  dropped 0  overruns 0  frame 0
  117.         TX packets 0  bytes 0 (0.0 B)
  118.         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
  120. lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
  121.         inet 127.0.0.1  netmask 255.0.0.0
  122.         inet6 ::1  prefixlen 128  scopeid 0x10<host>
  123.         loop  txqueuelen 0  (Local Loopback)
  124.         RX packets 0  bytes 0 (0.0 B)
  125.         RX errors 0  dropped 0  overruns 0  frame 0
  126.         TX packets 0  bytes 0 (0.0 B)
  127.         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

7. 迁移虚拟机

  1. 首先关闭虚拟机，命令如下：
  2. [root@kvm ~]# virsh shutdown test
  3. Domain test is being shutdown
  4. 查看虚拟机磁盘所在目录，命令如下：
  5. [root@kvm ~]# virsh domblklist test
  6. Target     Source
  7. ------------------------------------------------
  8. vda        /kvm_data/test.img
  9. vdb        /kvm_data/test_2.img
  10. hda        -
  11. [root@kvm ~]# virsh dumpxml test > /etc/libvirt/qemu/test03.xml 
  12. //如果是远程机器，需要把该配置文件拷贝到远程机器上
  13. [root@kvm ~]# rsync -av /kvm_data/test.img  /kvm_data/test03.img
  14. //-bash: rsync: command not found则yum install -y rsync
  15. //如果是迁移到远程，则需要把该磁盘文件拷贝到远程机器上
  16. sending incremental file list
  17. test.img
  18. sent 10,742,006,844 bytes  received 35 bytes  60,179,310.25 bytes/sec
  19. total size is 10,739,384,832  speedup is 1.00
  20. 因为是迁移到本机，配置文件用的是test子机的配置，不改会有冲突，所以需要修改该文件。如果是远程机器不用修改，命令如下：
  21. [root@kvm ~]# vi /etc/libvirt/qemu/test03.xml 
  22.  <name>test03</name>
  23. //修改domname: 
  24. //修改uuid（随便改一下数字，位数不要变）
  25.     <disk type='file' device='disk'>
  26.       <driver name='qemu' type='qcow2'/>
  27.       <source file='/kvm_data/test03.img'/>
  28.       <target dev='vda' bus='virtio'/>
  29.       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
  30.     </disk>
  31. //修改磁盘路径
  32. 定义新虚拟机，命令如下：
  33. [root@kvm ~]# virsh define /etc/libvirt/qemu/test03.xml  
  34. Domain test03 defined from /etc/libvirt/qemu/test03.xml
  35. 查看虚拟机列表，会发现新迁移的虚拟机test03，命令如下：
  36. [root@kvm ~]# virsh list --all
  37.  Id    Name                           State
  38. ----------------------------------------------------
  39.  6     test02                         running
  40.  -     test                           shut off
  41.  -     test03                         shut off