kvm之Linux虚拟机在线扩展磁盘

9780j · 发表于 2016-2-15 14:48:03

kvm虚拟机也支持在线扩展磁盘功能,在线扩展有特定的使用环境，主要用于不能随便停用的生产环境中，本文以hadoop为例具体步骤如下：1，查看现有磁盘

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[iyunv@KVM test]# virsh list --all
Id Name                         State
----------------------------------------------------
1    win7                         running
17 hadoop1                      running
18 hadoop4                      running
20 hadoop2                      running
-    hadoop3                      shut off
[iyunv@KVM test]# virsh domblklist hadoop1
Target    Source
------------------------------------------------
vda       /images/test/hadoop1.qcow2
hdc       -

2，创建一块qcow2虚拟磁盘

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[iyunv@KVM test]# qemu-img create -f qcow2 hadoop1_add01.qcow2 5G
Formatting 'hadoop1_add01.qcow2', fmt=qcow2 size=5368709120 encryption=off cluster_size=65536
[iyunv@KVM test]#

3，在线添加这台qcow2虚拟磁盘

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[iyunv@KVM test]# virsh attach-disk hadoop1 /images/test/hadoop1_add01.qcow2 vdb --cache=none --subdriver=qcow2
Disk attached successfully
[iyunv@KVM test]# virsh domblklist hadoop1
Target    Source
------------------------------------------------
vda       /images/test/hadoop1.qcow2
vdb       /images/test/hadoop1_add01.qcow2
hdc       -

4，进入虚拟机查看，如下图：
QQ截图20160215144641.png

5，然后进入系统里边划分区

fdisk /dev/vdb
QQ截图20160215144653.png

6,划分逻辑卷LVM省略，前边的可以参考。

7，修改虚拟机配置文件，把新增的磁盘配置写到虚拟机磁盘配置
（1）查看当前虚拟机hadoop1的磁盘配置

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[iyunv@KVM test]# virsh dumpxml hadoop1
<domain type='qemu' id='17'>
  <name>hadoop1</name>
  <uuid>919f0921-0736-ad5b-780b-a440de2f35cb</uuid>
  <memory unit='KiB'>524288</memory>
  <currentMemory unit='KiB'>524288</currentMemory>
  <vcpu placement='static'>1</vcpu>
  <os>
<type arch='x86_64' machine='rhel6.6.0'>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='qcow2' cache='none'/>
   <source file='/images/test/hadoop1.qcow2'/>
   <target dev='vda' bus='virtio'/>
   <alias name='virtio-disk0'/>
   <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
</disk>
<disk type='file' device='disk'>
   <driver name='qemu' type='qcow2' cache='none'/>
   <source file='/images/test/hadoop1_add01.qcow2'/>
   <target dev='vdb' bus='virtio'/>
   <alias name='virtio-disk1'/>
   <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
</disk>
<disk type='block' device='cdrom'>
   <driver name='qemu' type='raw'/>
   <target dev='hdc' bus='ide'/>
   <readonly/>
   <alias name='ide0-1-0'/>
   <address type='drive' controller='0' bus='1' target='0' unit='0'/>
</disk>
<controller type='usb' index='0' model='ich9-ehci1'>
   <alias name='usb0'/>
   <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x7'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci1'>
   <alias name='usb0'/>
   <master startport='0'/>
   <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0' multifunction='on'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci2'>
   <alias name='usb0'/>
   <master startport='2'/>
   <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x1'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci3'>
   <alias name='usb0'/>
   <master startport='4'/>
   <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x2'/>
</controller>
<controller type='ide' index='0'>
   <alias name='ide0'/>
   <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
</controller>
<interface type='bridge'>
   <mac address='52:54:00:b6:bf:1f'/>
   <source bridge='br0'/>
   <target dev='vnet1'/>
   <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/2'/>
   <target port='0'/>
   <alias name='serial0'/>
</serial>
<console type='pty' tty='/dev/pts/2'>
   <source path='/dev/pts/2'/>
   <target type='serial' port='0'/>
   <alias name='serial0'/>
</console>
<input type='mouse' bus='ps2'/>
<graphics type='vnc' port='5911' autoport='no' listen='0.0.0.0'>
   <listen type='address' address='0.0.0.0'/>
</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>
</domain>

（2）把以下配置添加到/etc/libvirt/qemu/hadoop1.xml配置文件中

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