故障现象：
docker进程僵死，docker命令无法使用
处理过程：
查看docker进程状态，显示句柄数过多，于是重启了docker
[root@data02 opt]# systemctl status docker● docker.service - Docker Application Container Engine Loaded: loaded(/usr/lib/systemd/system/docker.service;enabled;vendor preset: disabled)Active: active(running)since Tue2022-02-08 08:41:24 CST;1years5months ago Docs: https://docs.docker.com Main PID:821(dockerd)CGroup: /system.slice/docker.service ├─821/usr/bin/dockerd ├─1258docker-containerd--config/var/run/docker/containerd/containerd.toml Jul2710:28:49 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s Jul2710:28:50 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s Jul2710:28:51 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s Jul2710:28:52 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s Jul2710:28:53 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s Jul2710:28:54 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s Jul2710:28:55 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s Jul2710:28:56 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s Jul2710:28:57 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s Jul2710:28:58 data02 dockerd[821]: http: Accept error: accept unix /var/run/docker.sock: accept4: too manyopenfiles;retryingin1s执行systemctl restart docker命令之后，卡在命令行
查看docker状态和journalctl -xe，也没有发现明显报错。
[root@data02 ~]# systemctl status docker -l● docker.service - Docker Application Container Engine Loaded: loaded(/usr/lib/systemd/system/docker.service;enabled;vendor preset: disabled)Active: deactivating(stop-sigterm)since Thu2023-07-2710:38:18 CST;34min ago Docs: https://docs.docker.com Main PID:22539(dockerd)Memory:160.3M CGroup: /system.slice/docker.service ├─22539 /usr/bin/dockerd └─22546 docker-containerd--config/var/run/docker/containerd/containerd.toml Jul2711:02:15 data02 dockerd[22539]:time="2023-07-27T11:02:15+08:00"level=infomsg="loading plugin "io.containerd.grpc.v1.tasks"..."module=containerdtype=io.containerd.grpc.v1 Jul2711:02:15 data02 dockerd[22539]:time="2023-07-27T11:02:15+08:00"level=infomsg="loading plugin "io.containerd.grpc.v1.version"..."module=containerdtype=io.containerd.grpc.v1 Jul2711:02:15 data02 dockerd[22539]:time="2023-07-27T11:02:15+08:00"level=infomsg="loading plugin "io.containerd.grpc.v1.introspection"..."module=containerdtype=io.containerd.grpc.v1 Jul2711:02:15 data02 dockerd[22539]:time="2023-07-27T11:02:15+08:00"level=infomsg=serving...address="/var/run/docker/containerd/docker-containerd-debug.sock"module="containerd/debug"Jul2711:02:15 data02 dockerd[22539]:time="2023-07-27T11:02:15+08:00"level=infomsg=serving...address="/var/run/docker/containerd/docker-containerd.sock"module="containerd/grpc"Jul2711:02:15 data02 dockerd[22539]:time="2023-07-27T11:02:15+08:00"level=infomsg="containerd successfully booted in 0.013187s"module=containerd Jul2711:02:15 data02 dockerd[22539]:time="2023-07-27T11:02:15.810108948+08:00"level=infomsg="[graphdriver] using prior storage driver: overlay2"Jul2711:02:15 data02 dockerd[22539]:time="2023-07-27T11:02:15.835765459+08:00"level=infomsg="Graph migration to content-addressability took 0.00 seconds"Jul2711:02:15 data02 dockerd[22539]:time="2023-07-27T11:02:15.836814381+08:00"level=infomsg="Loading containers: start."先stop掉docker后，ps 发现还有几个进程没有停掉。
手动kill掉进程后，再次启动，成功。
docker服务异常停止，重启docker后，容器启动失败
docker启动的时候，会在运行目录（/var/run/docker/runtime-runc/moby）（不同环境，可能目录不一样，可以通过find / -name ‘容器ID’ 查找）下生成以docker-ID，因为docker异常停止，改容器文件并没有删除，所以启动的时候，会报错该容器已存在