如何清理虚拟机缓存文件
1. 首先需要在真机安装 virt-sysprep命令
yum whatprovides */virt-sysprep
yum install libguestfs-tools -y
2. 清理虚拟机临时及缓存文件命令：
cd /var/lib/libvirt/images/
virt-sysprep -d 虚拟机名
3. 有时它会报错，信息如下：
[ 0.0] examining the guest ...
virt-sysprep: error: libguestfs error: could not create appliance through
libvirt.
try running qemu directly without libvirt using this environment variable:
export libguestfs_backend=direct
original error from libvirt: \u4e0d\u652f\u6301\u7684\u914d\u7f6e\uff1ashared access for disk
'sdb' requires use of supported storage format [code=67 int1=-1]
if reporting bugs, run virt-sysprep with debugging enabled and include the
complete output:
virt-sysprep -v -x [...]
解决：执行下面命令更新包即可
yum upgrade libguestfs-tools
virt-sysprep -d 虚拟机名