KVM--虚拟机在线扩展磁盘（八）

Kevin song

发布于 2022-06-07 18:17:37

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发布于 2022-06-07 18:17:37

文章被收录于专栏：运维监控日志分析运维监控日志分析

KVM虚拟机磁盘在线扩容的两种方法：

通过 virsh blockresize 命令扩容当前磁盘
通过 virsh attach-disk 命令在线添加硬盘设备到虚拟机

virsh blockresize 扩容

1，查看虚拟机磁盘信息

[root@kvm-node1 ~]# virsh domblklist win10
Target     Source
------------------------------------------------
vda        /kvm/img/win10.img
hda        /kvm/iso/virtio-win-0.1.215.iso

2，磁盘扩容

（1）查看当前磁盘信息

（2）win10虚拟机磁盘80G扩容100G

virsh blockresize win10 /kvm/img/win10.img 100G

3，登录虚拟机，磁盘扩容

（1）查看扩容磁盘和C盘空间

（2）C盘扩容

（3）验证磁盘扩容空间

virsh attach-disk扩容

1，查看虚拟机，磁盘

[root@kvm-node1 opt]# virsh list --all
 Id    Name                           State
----------------------------------------------------
 14    win10                          running
 45    vm01                           running
 -     node01                         shut off
[root@kvm-node1 opt]# virsh domblklist vm01
Target     Source
------------------------------------------------
vda        /kvm/img/vm01.qcow2

2，创建一块qcow2虚拟磁盘

[root@kvm-node1]# qemu-img create -f qcow2   /kvm/img/vm01_add01.qcow2 5G
Formatting '/kvm/img/vm01_add01.qcow2', fmt=qcow2 size=5368709120 encryption=off cluster_size=65536 lazy_refcounts=off

3，在线添加qcow2虚拟磁盘

[root@kvm-node1 /]# virsh attach-disk  vm01 /kvm/img/vm01_add01.qcow2 vdb --cache=none --subdriver=qcow2
Disk attached successfully
[root@kvm-node1 /]# virsh domblklist vm01
Target     Source
------------------------------------------------
vda        /kvm/img/vm01.qcow2
vdb        /kvm/img/vm01_add01.qcow2

4，进入虚拟机验证

virsh console   vm01

5，进入虚拟机创建分区

（1）创建分区

[root@localhost ~]# fdisk  /dev/vdb
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0x87b41dc1.

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p
Partition number (1-4, default 1): 
First sector (2048-10485759, default 2048): 
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-10485759, default 10485759): 
Using default value 10485759
Partition 1 of type Linux and of size 5 GiB is set

Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
[358593.363604]  vdb: vdb1
Syncing disks.

（2）创建PV

将物理硬盘格式化成PV（物理卷）使用pvcreate命令

[root@localhost ~]# pvcreate /dev/vdb1
  Physical volume "/dev/vdb1" successfully created.

查看当前vg信息

（3）扩容VG

把转换好的物理卷并到vg（卷组）中，使用vgcreate命令

[root@localhost ~]# vgextend  centos /dev/vdb1
  Volume group "centos" successfully extended

（4）扩容LV

查看逻辑卷，选择对应逻辑卷路径

（5）扩容当前逻辑卷空间

[root@localhost ~]# lvextend /dev/centos/root /dev/vdb1 
  Size of logical volume centos/root changed from 10.00 GiB (2560 extents) to <15.00 GiB (3839 extents).
  Logical volume centos/root successfully resized.

（6）写入文件系统，使扩容生效

使用ext文件系统，可以使用resize2fs命令替换xfs_growfs命令

（7）查看LVM信息

[root@localhost ~]# pvs
  PV         VG     Fmt  Attr PSize   PFree 
  /dev/vda2  centos lvm2 a--  <19.51g <5.51g
  /dev/vdb1  centos lvm2 a--   <5.00g     0

（8）查看根分区扩容效果

6，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，避免重启丢失

（1）查看当前虚拟机vm01的磁盘配置

[root@kvm-node1 /]# virsh dumpxml vm01

（2）编辑虚拟机配置文件virsh edit vm01

<disk type='file' device='disk'>
      <driver name='qemu' type='qcow2' cache='none'/>
      <source file='/kvm/img/vm01_add01.qcow2'/>
      <target dev='vdb' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
    </disk>