从头启动Microsoft SQL Server（在Linux上）容器后...
$ docker run -e 'ACCEPT_EULA=Y' -e 'SA_PASSWORD=Pa$$word' -p 1433:1433 \
-d --name mssql microsoft/mssql-server-linux
...创建Docker 检查点 ...
$ docker checkpoint create mssql cp1
...失败：
Error response from daemon: Cannot checkpoint container mssql:
failed to read checkpoint reader:
open /var/lib/docker/containers/f2eb8d17e95630332bbeab887b9e03a1b91efcd8907f69b82805a788331316e2/checkpoints/cp1/cgroup.img:
no such file or directory
这是在Ubuntu 18.04上，安装了CRIU并启用了实验模式：
$ docker version
Client:
Version: 18.09.6
API version: 1.39
Go version: go1.10.8
Git commit: 481bc77
Built: Sat May 4 02:35:57 2019
OS/Arch: linux/amd64
Experimental: false
Server: Docker Engine - …