1、虚拟机关机

virsh shutdown ${vm_name}

2、执行磁盘扩容命令，qemu-img resize xxx.qcow2 +100G

找到虚拟机对应的硬盘文件执行
qemu-img resize ${vm_name}.qcow2 +100G

3、虚拟机开机

virsh start ${vm_name}

4、安装growpart

kvm所在主机安装
yum install -y epel-release
yum install cloud-utils-growpart

5、磁盘扩容

growpart /dev/vda 2

6、文件系统扩容

xfs_growfs /dev/vda 2 # xfs
resize2fs /dev/vda 2 # ext4