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使用指令接口對KVM虛拟機進行簡單的管理

一 KVM對使用者提供的指令主要在/usr/bin/目錄下

[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-image      /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

常用的指令有:virsh,virsh-install,virsh-clone,virsh-convert,virsh-image,qemu-img和qemu-kvm

二 virsh常用的管理指令

使用xml配置檔案開啟虛拟機

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

Domain 1003vm created from 1003vm.xml

列出虛拟機:

[root@centoskvm kvm]# virsh list

 Id   Name              State

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

 13   1003vm             running

Id和Name可以作為控制虛拟機的主鍵

列出域中全部的虛拟機:

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

 -   1001vm             shut off

關閉虛拟機:

[root@centoskvm kvm]# virsh shutdown 13

或者

[root@centoskvm kvm]# virsh shutdown  1003vm

重新開機虛拟機:

[root@centoskvm kvm]#virsh reboot 13

[root@centoskvm kvm]# virsh reboot  1003vm

強制關閉虛拟機:(不建議使用,這樣容易破壞虛拟機的檔案系統)

[root@centoskvm kvm]#virsh destroy 13

[root@centoskvm kvm]# virsh destroy 1003vm

添加虛拟機:

[root@centoskvm kvm]#virsh define /home/kvm/1002vm.xml #根據主機配置文檔添加虛拟機

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

 -   1002vm             shut off  #1002vm已被添加到域中

移除虛拟機:

[root@centoskvm kvm]#virsh undefine 1002vm 

Domain 1002vm has been undefined

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

#1002vm已被從域中移除

導出虛拟機的配置資訊xml檔案

[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'>

   <target type='serial' port='0'/>

  </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>

  <imagelabel>system_u:object_r:svirt_image_t:s0:c97,c672</imagelabel>

 </seclabel>

</domain>

也可以使用xml配置來啟動虛拟機:

[root@centoskvm kvm]# virsh shutdown 1003vm

 -   1003vm              shut off

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

 14   1003vm             running

三 使用指令接口建立虛拟機

建立鏡像檔案:

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

檢視img檔案資訊:

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

image: 1001vm.img

file format: qcow2

virtual size: 16G (17179869184 bytes)

disk size: 5.9G

cluster_size: 65536

其中參數 -f 表示鏡像檔案的格式[qcow2],具體介紹如下:

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

create: invalid option -- '-'

qemu-img version 0.12.1, Copyright (c) 2004-2008 Fabrice Bellard

usage: qemu-img command [command options]

QEMU disk image 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 image filename

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

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

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

 'size' is the disk image 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 image 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 image must be compressed (qcow format only)

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

    match exactly. The image 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 image 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 image

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

常用的格式為raw和qcow2,推薦使用qcow2格式。

raw格式:可以簡單、容易地導出到其它模拟器中,但是立即配置設定占用空間大。

qcow2格式:是qcow格式的更新版本,是目前最萬能的格式。使用它可獲得較小映像,也是虛拟池一直在使用的鏡像格式,支援鏡像快照,友善的恢複管理。

安裝虛拟機客戶作業系統:

[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 image

  --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

  -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登入虛拟機

[root@centoskvm img]#virsh list

[root@centoskvm img]# virshconsole 13

若出現無法從console登入的情況,會卡在“

Escape character is ^]”處無法繼續。請從桌面以root登入做如下操作:

1、添加ttyS0的安全許可,允許root登入:

[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檔案中為核心添加參數: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

splashimage=(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:

4、重新開機客戶虛拟機:

[root@1001vm img]# reboot

此時,再次嘗試console指令可以正常使用:

[root@centoskvm img]# virsh console 1001vm

Connected to domain 1001vm

Escape character is ^]

[  OK  ]

Setting hostname 1001vm:  [  OK  ]

Setting up Logical Volume Management:  2 logical volume(s) in volume group "vg_1001vm" now active

。。。。。。。。。。。。。。。。。。。。。。。。。。。。

Starting atd: [  OK  ]

Starting up CIM server: [  OK  ]

CentOS release 6.2 (Final)

Kernel 2.6.32-220.el6.x86_64 on an x86_64

1001vm login: root

Password: 

[root@1001vm ~]#

本文轉自silence部落格51CTO部落格,原文連結http://blog.51cto.com/silencezone/1944578如需轉載請自行聯系原作者

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