docker安装报错Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

docker安装完成后，执行docker version报错

[root@clroot local]# docker version
Client: Docker Engine - Community
 Version:           20.10.1
 API version:       1.41
 Go version:        go1.13.15
 Git commit:        831ebea
 Built:             Tue Dec 15 04:37:17 2020
 OS/Arch:           linux/amd64
 Context:           default
 Experimental:      true
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

执行如下命令

[root@clroot local]# systemctl daemon-reload
[root@clroot local]# systemctl restart docker.service

再次执行docker version成功