使用命令接口对KVM虚拟机进行简单的管理

最新推荐文章于 2022-11-25 13:53:26 发布

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最新推荐文章于 2022-11-25 13:53:26 发布

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文章标签：运维操作系统 python

原文链接：http://blog.51cto.com/silencezone/1944578

一 KVM对用户提供的命令主要在/usr/bin/目录下

[root@centoskvm ~]# ls /usr/bin/vir*

/usr/bin/virsh /usr/bin/virt-manager

/usr/bin/virt-clone /usr/bin/virt-pki-validate

/usr/bin/virt-convert /usr/bin/virt-top

/usr/bin/virt-host-validate /usr/bin/virt-viewer

/usr/bin/virt-p_w_picpath /usr/bin/virt-who

/usr/bin/virt-install /usr/bin/virt-xml-validate

[root@centoskvm ~]# ls /usr/bin/qe*

/usr/bin/qemu-img /usr/bin/qemu-io /usr/bin/qemu-kvm

常用的命令有:virsh,virsh-install,virsh-clone,virsh-convert,virsh-p_w_picpath,qemu-img和qemu-kvm

二 virsh常用的管理命令

使用xml配置文件开启虚拟机

[root@centoskvm kvm]# virsh create 1003vm.xml

Domain 1003vm created from 1003vm.xml

列出虚拟机：

[root@centoskvm kvm]# virsh list

Id Name State

----------------------------------------------------

13 1003vm running

Id和Name可以作为控制虚拟机的主键

列出域中全部的虚拟机：

[root@centoskvm kvm]# virsh list --all

Id Name State

----------------------------------------------------

13 1003vm running

- 1001vm shut off

关闭虚拟机：

[root@centoskvm kvm]# virsh shutdown 13

或者

[root@centoskvm kvm]# virsh shutdown 1003vm

重启虚拟机：

[root@centoskvm kvm]#virsh reboot 13

或者

[root@centoskvm kvm]# virsh reboot 1003vm

强制关闭虚拟机：（不建议使用，这样容易破坏虚拟机的文件系统）

[root@centoskvm kvm]#virsh destroy 13

或者

[root@centoskvm kvm]# virsh destroy 1003vm

添加虚拟机：

[root@centoskvm kvm]#virsh define /home/kvm/1002vm.xml #根据主机配置文档添加虚拟机

Domain 1002vm defined from /home/kvm/1002vm.xml

[root@centoskvm kvm]# virsh list --all

Id Name State

----------------------------------------------------

13 1003vm running

- 1001vm shut off

- 1002vm shut off #1002vm已被添加到域中

移除虚拟机：

[root@centoskvm kvm]#virsh undefine 1002vm

Domain 1002vm has been undefined

[root@centoskvm kvm]# virsh list --all

Id Name State

----------------------------------------------------

13 1003vm running

- 1001vm shut off

#1002vm已被从域中移除

导出虚拟机的配置信息xml文件

[root@centoskvm kvm]# virsh dumpxml 1003vm > ~/1003vm.xml

[root@centoskvm kvm]# cat ~/1003vm.xml

<domaintype='kvm' id='13'>

<name>1003vm</name>

<uuid>323286df-2fa9-9864-4754-b51df76bd336</uuid>

<memory unit='KiB'>2097152</memory>

<currentMemory unit='KiB'>2097152</currentMemory>

<vcpu placement='static'>2</vcpu>

<os>

<type arch='x86_64' machine='rhel6.2.0'>hvm</type>

<boot dev='hd'/>

</os>

<features>

<acpi/>

<apic/>

<pae/>

</features>

<clock offset='utc'/>

<on_poweroff>destroy</on_poweroff>

<on_reboot>restart</on_reboot>

<on_crash>restart</on_crash>

<devices>

<emulator>/usr/libexec/qemu-kvm</emulator>

<disk type='file' device='disk'>

<driver name='qemu' type='raw' cache='none'/>

<source file='/home/kvm/1003vm.img'/>

<target dev='vda' bus='virtio'/>

<shareable/>

<alias name='virtio-disk0'/>

<address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>

</disk>

<controller type='usb' index='0'>

<alias name='usb0'/>

<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>

</controller>

<interface type='bridge'>

<mac address='52:54:00:88:f8:03'/>

<source bridge='br0'/>

<target dev='vnet0'/>

<model type='virtio'/>

<alias name='net0'/>

<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>

</interface>

<serial type='pty'>

<source path='/dev/pts/1'/>

<target port='0'/>

<alias name='serial0'/>

</serial>

<console type='pty' tty='/dev/pts/1'>

<source path='/dev/pts/1'/>

<target type='serial' port='0'/>

<alias name='serial0'/>

</console>

<input type='tablet' bus='usb'>

<alias name='input0'/>

</input>

<input type='mouse' bus='ps2'/>

<graphics type='vnc' port='5900' listen='127.0.0.1'>

<listen type='address' address='127.0.0.1'/>

</graphics>

<video>

<model type='cirrus' vram='9216' heads='1'/>

<alias name='video0'/>

<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>

</video>

<memballoon model='virtio'>

<alias name='balloon0'/>

<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>

</memballoon>

</devices>

<seclabel type='dynamic' model='selinux' relabel='yes'>

<label>system_u:system_r:svirt_t:s0:c97,c672</label>

<p_w_picpathlabel>system_u:object_r:svirt_p_w_picpath_t:s0:c97,c672</p_w_picpathlabel>

</seclabel>

</domain>

也可以使用xml配置来启动虚拟机：

[root@centoskvm kvm]# virsh shutdown 1003vm

[root@centoskvm kvm]# virsh list --all

Id Name State

----------------------------------------------------

- 1003vm shut off

- 1001vm shut off

[root@centoskvm kvm]# virsh create ~/1003vm.xml

[root@centoskvm kvm]# virsh list --all

Id Name State

----------------------------------------------------

14 1003vm running

- 1001vm shut off

三使用命令接口创建虚拟机

创建镜像文件：

[root@centoskvm kvm]# qemu-img create -f qcow2 /home/kvm/1001vm.img 16G

查看img文件信息：

[root@centoskvm img]# qemu-img info 1001vm.img

p_w_picpath: 1001vm.img

file format: qcow2

virtual size: 16G (17179869184 bytes)

disk size: 5.9G

cluster_size: 65536

其中参数 -f 表示镜像文件的格式[qcow2]，具体介绍如下：

[root@centoskvm img]# qemu-img create --help

create: invalid option -- '-'

usage: qemu-img command [command options]

QEMU disk p_w_picpath utility

Command syntax:

check [-f fmt] filename

create [-f fmt] [-o options] filename [size]

commit [-f fmt] [-t cache] filename

convert [-c] [-p] [-f fmt] [-t cache] [-O output_fmt] [-o options] [-S sparse_size] filename [filename2 [...]] output_filename

info [-f fmt] filename

snapshot [-l | -a snapshot | -c snapshot | -d snapshot] filename

rebase [-f fmt] [-t cache] [-p] [-u] -b backing_file [-F backing_fmt] filename

resize filename [+ | -]size

Command parameters:

'filename' is a disk p_w_picpath filename

'fmt' is the disk p_w_picpath format. It is guessed automatically in most cases

'cache' is the cache mode used to write the output disk p_w_picpath, the valid

options are: 'none', 'writeback' (default), 'writethrough' and 'unsafe'

'size' is the disk p_w_picpath size in bytes. Optional suffixes

'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M)

and T (terabyte, 1024G) are supported. 'b' is ignored.

'output_filename' is the destination disk p_w_picpath filename

'output_fmt' is the destination format

'options' is a comma separated list of format specific options in a

name=value format. Use -o ? for an overview of the options supported by the

used format

'-c' indicates that target p_w_picpath must be compressed (qcow format only)

'-u' enables unsafe rebasing. It is assumed that old and new backing file

match exactly. The p_w_picpath doesn't need a working backing file before

rebasing in this case (useful for renaming the backing file)

'-h' with or without a command shows this help and lists the supported formats

'-p' show progress of command (only certain commands)

'-S' indicates the consecutive number of bytes that must contain only zeros

for qemu-img to create a sparse p_w_picpath during conversion

Parameters to snapshot subcommand:

'snapshot' is the name of the snapshot to create, apply or delete

'-a' applies a snapshot (revert disk to saved state)

'-c' creates a snapshot

'-d' deletes a snapshot

'-l' lists all snapshots in the given p_w_picpath

Supported formats: raw cow qcow vdi vmdk cloop dmg bochs vpc vvfat qcow2 qed parallels nbd blkdebug host_cdrom host_floppy host_device file

常用的格式为raw和qcow2，推荐使用qcow2格式。

raw格式：可以简单、容易地导出到其它模拟器中，但是立即分配占用空间大。

qcow2格式：是qcow格式的升级版本，是目前最万能的格式。使用它可获得较小映像，也是虚拟池一直在使用的镜像格式，支持镜像快照，方便的恢复管理。

安装虚拟机客户操作系统：

[root@centoskvm img]#virt-install --name 1001vm --ram=1024 --arch=x86_64 --vcpus=2 --check-cpu --os-type=linux --os-variant='rhel6' -c /home/mysoft/os/CentOS-6.2-x86_64-bin-DVD1.iso --disk path=/home/img/1001vm.img,device=disk,bus=virtio,format=qcow2 --bridge=br0 --noautoconsole --vnc --vncport=5902 --vnclisten=0.0.0.0

[root@centoskvm img]# virt-install --help

Usage: virt-install --name NAME --ram RAM STORAGE INSTALL [options]

Options:

--version show program's version number and exit

-h, --help show this help message and exit

--connect=URI Connect to hypervisor with libvirt URI

General Options:

-n NAME, --name=NAME

Name of the guest instance

-r MEMORY, --ram=MEMORY

Memory to allocate for guest instance in megabytes

--vcpus=VCPUS Number of vcpus to configure for your guest. Ex:

--vcpus 5

--vcpus 5,maxcpus=10

--vcpus sockets=2,cores=4,threads=2

--cpuset=CPUSET Set which physical CPUs domain can use.

--cpu=CPU CPU model and features. Ex: --cpu coreduo,+x2apic

--description=DESCRIPTION

Human readable description of the VM to store in the

generated XML.

--security=SECURITY

Set domain security driver configuration.

--numatune=NUMATUNE

Tune NUMA policy for the domain process.

Installation Method Options:

-c CDROM, --cdrom=CDROM

CD-ROM installation media

-l LOCATION, --location=LOCATION

Installation source (eg, nfs:host:/path,

http://host/path, ftp://host/path)

--pxe Boot from the network using the PXE protocol

--import Build guest around an existing disk p_w_picpath

--init=INIT Path to init binary for container guest. Ex:

--init /path/to/app (to contain an application)

--init /sbin/init (for a full OS container)

--livecd Treat the CD-ROM media as a Live CD

-x EXTRA, --extra-args=EXTRA

Additional arguments to pass to the install kernel

booted from --location

--initrd-inject=INITRD_INJECTIONS

Add given file to root of initrd from --location

--os-type=DISTRO_TYPE

The OS type being installed, e.g. 'linux', 'unix',

'windows'

--os-variant=DISTRO_VARIANT

The OS variant being installed guests, e.g. 'fedora6',

'rhel5', 'solaris10', 'win2k'

--boot=BOOTOPTS Optionally configure post-install boot order, menu,

permanent kernel boot, etc.

Storage Configuration:

--disk=DISKOPTS Specify storage with various options. Ex.

--disk path=/my/existing/disk

--disk path=/my/new/disk,size=5 (in gigabytes)

--disk vol=poolname:volname,device=cdrom,bus=scsi,...

--nodisks Don't set up any disks for the guest.

--filesystem=FILESYSTEMS

Pass host directory to the guest. Ex:

--filesystem /my/source/dir,/dir/in/guest

--filesystem template_name,/,type=template

Networking Configuration:

-w NETWORK, --network=NETWORK

Configure a guest network interface. Ex:

--network bridge=mybr0

--network network=my_libvirt_virtual_net

--network network=mynet,model=virtio,mac=00:11...

--nonetworks Don't create network interfaces for the guest.

Graphics Configuration:

--graphics=GRAPHICS

Configure guest display settings. Ex:

--graphics vnc

--graphics spice,port=5901,tlsport=5902

--graphics none

--graphics vnc,password=foobar,port=5910,keymap=ja

--noautoconsole Don't automatically try to connect to the guest

console

Device Options:

--serial=SERIALS Configure a guest serial device

--parallel=PARALLELS

Configure a guest parallel device

--channel=CHANNELS Configure a guest communication channel

--console=CONSOLES Configure a text console connection between the guest

and host

--host-device=HOSTDEVS

Configure physical host devices attached to the guest

--soundhw=SOUNDHW Configure guest sound device emulation

--watchdog=WATCHDOG

Configure a guest watchdog device

--video=VIDEO Configure guest video hardware.

--smartcard=SMARTCARD

Configure a guest smartcard device. Ex:

--smartcard mode=passthrough

Virtualization Platform Options:

-v, --hvm This guest should be a fully virtualized guest

-p, --paravirt This guest should be a paravirtualized guest

--container This guest should be a container guest

--virt-type=HV_TYPE

Hypervisor name to use (kvm, qemu, xen, ...)

--arch=ARCH The CPU architecture to simulate

--machine=MACHINE The machine type to emulate

--noapic Disables APIC for fully virtualized guest (overrides

value in os-type/os-variant db)

--noacpi Disables ACPI for fully virtualized guest (overrides

value in os-type/os-variant db)

-u UUID, --uuid=UUID

UUID for the guest.

Miscellaneous Options:

--autostart Have domain autostart on host boot up.

--print-xml Print the generated domain XML rather than define the

guest.

--print-step=XMLSTEP

Print XML of a specific install step (1, 2, 3, all)

rather than define the guest.

--noreboot Don't boot guest after completing install.

--wait=WAIT Time to wait (in minutes)

--dry-run Run through install process, but do not create devices

or define the guest.

--force Forces 'yes' for any applicable prompts, terminates

for all others

-q, --quiet Suppress non-error output

--prompt Request user input for ambiguous situations or

required options.

-d, --debug Print debugging information

四使用console登录虚拟机

[root@centoskvm img]#virsh list

Id Name State

----------------------------------------------------

13 1003vm running

[root@centoskvm img]# virshconsole 13

若出现无法从console登录的情况，会卡在“

Escape character is ^]”处无法继续。请从桌面以root登录做如下操作：

1、添加ttyS0的安全许可，允许root登录:

[root@1001vm img]# echo "ttyS0" >> /etc/securetty

[root@1001vm ~]# cat /etc/securetty

console

vc/1

vc/2

。。。。。。

vc/10

vc/11

tty1

tty2

。。。。。。

tty11

ttyS0

2、在/etc/grub.conf文件中为内核添加参数:console=ttyS0

[root@1001vm ~]# cat /etc/grub.conf

# grub.conf generated by anaconda

# Note that you do not have to rerun grub after making changes to this file

# NOTICE: You have a /boot partition. This means that

# all kernel and initrd paths are relative to /boot/, eg.

# root (hd0,0)

# kernel /vmlinuz-version ro root=/dev/mapper/vg_1001vm-lv_root

# initrd /initrd-[generic-]version.img

#boot=/dev/vda

default=0

timeout=5

splashp_w_picpath=(hd0,0)/grub/splash.xpm.gz

hiddenmenu

title CentOS (2.6.32-220.el6.x86_64)

root (hd0,0)

kernel /vmlinuz-2.6.32-220.el6.x86_64 ro root=/dev/mapper/vg_1001vm-lv_root rd_NO_LUKS rd_LVM_LV=vg_1001vm/lv_root LANG=en_US.UTF-8 rd_NO_MD quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_LVM_LV=vg_1001vm/lv_swap KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM console=ttyS0

initrd /initramfs-2.6.32-220.el6.x86_64.img

3、在/etc/inittab中添加agetty:

S0:12345:respawn:/sbin/agetty ttyS0 115200

[root@1001vm ~]# cat /etc/inittab

# inittab is only used by upstart for the default runlevel.

#。。。。。。。。。。。。。

id:5:initdefault:

S0:12345:respawn:/sbin/agetty ttyS0 115200

4、重启客户虚拟机:

[root@1001vm img]# reboot

此时，再次尝试console命令可以正常使用:

[root@centoskvm img]# virsh console 1001vm