kvm 基本运维命令

一、查询命令

1.列出所有的虚拟机

virsh list –all

2.显示虚拟机信息

virsh dominfo kvm-1

3.显示虚拟机内存和cpu的使用情况

yum install virt-top -y

virt-top

4.显示虚拟机分区信息

virt-df kvm-1

5.关闭虚拟机（shutodwn）

virsh shutdown kvm-1

6.启动虚拟机

virsh start kvm-1

7.设置虚拟机（kvm-1）跟随系统自启

virsh autostart kvm-1

8. 关闭虚拟及自启

virsh autostart --disable kvm-1

9.删除虚拟机

(当在安装虚拟机中系统过程中，没有安装成功，必须是删除了才能重新安装，不然会一直调用系统、驱动、空磁盘文件)

virsh undefine kvm-1

9.1. 查看列表定位要删除的虚拟机

virsh list –all

kvm 基本运维命令

9.2.强制停止虚拟机

virsh destroy vm4

kvm 基本运维命令

9.3. 删除虚拟机

virsh undefined vm4

kvm 基本运维命令

9.4. 更新当前文件，并查找包含虚拟机vm4的所有内容

updatedb

kvm 基本运维命令

9.5. 删除和vm4一切相关的内容

kvm 基本运维命令

9.6. 更新本机文件后继续查找，确保vm4相关文件彻底删除

kvm 基本运维命令

10.通过控制窗口登录虚拟机

virsh console kvm-1

二、给虚拟机添加硬盘

1.添加硬盘（lvm卷）或者USB到虚拟机上

virsh attach-disk kvm-1 /dev/sdb vbd --driver qemu --mode shareable

使用完成之后可以卸载usb

virsh detach-disk kvm vdb

2. 添加lvm卷，并挂载

[root@sh-kvm-1 ~]# lvcreate -n kvm-1-data -L 50G vg_shkvm1

[root@sh-kvm-1 ~]# virsh attach-disk kvm-1 /dev/vg_shkvm1/kvm-1-data vdb --driver qemu --mode shareable

Disk attached successfully

# 登录到kvm-1上查看lvm是否已经被挂载

[root@sh-kvm-1 ~]# virsh console kvm-1 # 输入kvm-1的用户和密码

[root@sh-kvm-1-1 ~]# fdisk -l # 查看硬盘挂载情况

Disk /dev/vda: 21.5 GB, 21474836480 bytes

16 heads, 63 sectors/track, 41610 cylinders

Units = cylinders of 1008 * 512 = 516096 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00058197

Device Boot Start End Blocks Id System

/dev/vda1 * 3 1018 512000 83 Linux

Partition 1 does not end on cylinder boundary.

/dev/vda2 1018 41611 20458496 8e Linux LVM

Partition 2 does not end on cylinder boundary.

Disk /dev/mapper/VolGroup-lv_root: 18.8 GB, 18798870528 bytes

255 heads, 63 sectors/track, 2285 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_swap: 2147 MB, 2147483648 bytes

255 heads, 63 sectors/track, 261 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00000000

Disk /dev/vdb: 53.7 GB, 53687091200 bytes # 新添加的硬盘

16 heads, 63 sectors/track, 104025 cylinders

Units = cylinders of 1008 * 512 = 516096 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00000000

3. 格式化新添加的vdb，并添加到lvm组中

# 对新添加的硬盘分区

[root@sh-kvm-1-1 ~]# fdisk /dev/vdb

Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel

Building a new DOS disklabel with disk identifier 0xf04b6807.

Changes will remain in memory only, until you decide to write them.

After that, of course, the previous content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to

switch off the mode (command 'c') and change display units to

sectors (command 'u').

Command (m for help): m # 查看帮助

Command action

a toggle a bootable flag

b edit bsd disklabel

c toggle the dos compatibility flag

d delete a partition

l list known partition types

m print this menu

n add a new partition

o create a new empty DOS partition table

p print the partition table

q quit without saving changes

s create a new empty Sun disklabel

t change a partition's system id

u change display/entry units

v verify the partition table

w write table to disk and exit

x extra functionality (experts only)

Command (m for help): n #添加一个分区

Command action

e extended

p primary partition (1-4)

p #选择添加一个扩展分区

Partition number (1-4):

Value out of range.

Partition number (1-4): 1

First cylinder (1-104025, default 1):

Using default value 1

Last cylinder, +cylinders or +size{K,M,G} (1-104025, default 104025):

Using default value 104025

Command (m for help): t #改变分区的格式

Selected partition 1

Hex code (type L to list codes): 8e #改成lvm

Changed system type of partition 1 to 8e (Linux LVM)

Command (m for help): w # 保存更改

root@sh-kvm-1-1 ~]# mkfs.ext4 /dev/vdb1 # 格式化分区

mke2fs 1.41.12 (17-May-2010)

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

Stride=0 blocks, Stripe width=0 blocks

3276800 inodes, 13107142 blocks

655357 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=4294967296

400 block groups

32768 blocks per group, 32768 fragments per group

8192 inodes per group

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,

4096000, 7962624, 11239424

Writing inode tables: done

Creating journal (32768 blocks): done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 28 mounts or

180 days, whichever comes first. Use tune2fs -c or -i to override.

[root@sh-kvm-1-1 ~]# pvc reate /dev/vdb1 # 创建pv

vdb vdb1

[root@sh-kvm-1-1 ~]# vgextend VolGroup /dev/vdb # 扩展lvm vg

vdb vdb1

[root@sh-kvm-1-1 ~]# vgs

VG #PV #LV #SN Attr VSize VFree

VolGroup 2 2 0 wz--n- 69.50g 50.00g

# 从上面能看出，新添加的已经加到lvm组中

三、改变虚拟机的参数

1.通过命令行更改创建之后虚拟机的内存，cpu等信息

1.1更改内存

1. 查看虚拟机当前内存

[root@sh-kvm-1 ~]# virsh dominfo kvm-1 | grep memory

Max memory: 4194304 KiB

Used memory: 4194304 KiB

# 2、动态设置内存为512MB，内存减少

virsh setmem kvm-1 524288

# 注意单位必须是KB

# 3、查看内存变化

# virsh dominfo kvm-1 | grep memory

Max memory: 14194304 KiB

Used memory: 524288 kiB

# 4、内存增加

virsh shutdown kvm-1

virsh edit kvm-1 # 直接更改memory

virsh create /etc/libvirt/demu/kvm-1/xml

# 之后操作1,2,3步骤增加内存

2. 更改CPU

需要修改配置文件，因此需要停止虚拟机

virsh shutdown kvm-1

virsh edit kvm-1

# <vcpu>2</vcpu> # 4 > 2

virsh create /etc/libvirt/demu/kvm-1/xml

3. 硬盘扩容

1. Create a 10-GB non-sparse file:

# dd if=/dev/zero of=/vm-images/vm1-add.img bs=1M count=10240

2. Shutdown the VM:

# virsh shutdown vm1

3. Add an extra entry for ‘disk’ in the VM's XML file in /etc/libvirt/qemu. You can look copy & paste

the entry for your mail storage device and just change the target and address tags. For example:

# virsh edit vm1

<address type='pci' domain='0x0000' bus='0x00' slot='0x04'

function='0x0'/>

</disk>

Add:

<address type='pci' domain='0x0000' bus='0x00' slot='0x06'

function='0x0'/>

</disk>

# 这里建议使用上面的添加硬盘的方式添加