问题：跟往常一样执行docker-compos exec redis sh时出现如下错误，而容器是运行状态中。
# docker-compose exec redis shrpc error: code = 2 desc = oci runtime error: exec failed: container_linux.go:247: starting container process caused "process_linux.go:75: starting setns process caused \"fork/exec /proc/self/exe: no such file or directory\""
解决办法：
1、获取容器ID
# docker ps | grep arcs_redis_1ac248a3c5c0e redis:alpine "docker-entrypoint..." 2 years ago Up 16 minutes 6379/tcp arcs_redis_1
2、通过容器ID获取容器的PID
# ps -ef|grep libcontainerd | grep ac248a3c5c0eroot 6650 9053 0 11:14 ? 00:00:00 docker-containerd-shim ac248a3c5c0e3f6405c35e186b5d095aeb7af72b0f52bb08303baded251cdb61 /var/run/docker/libcontainerd/ac248a3c5c0e3f6405c35e186b5d095aeb7af72b0f52bb08303baded251cdb61 docker-runc 注：第二个字段为容器的PID
3、获取容器的mount位置
# grep "path" /var/run/docker/libcontainerd/ac248a3c5c0e3f6405c35e186b5d095aeb7af72b0f52bb08303baded251cdb61/config.json 注：mount的路径：{"path":"/var/lib/docker/devicemapper/mnt/cc2ff9576cdf7736acca50ffdaadef471e01a8ffe9acb039c1d423edd941bd38/rootfs"}，此路径用于第6步挂载时使用。 ４、用nsenter进入容器的namespace
# nsenter -m -t 6650 bash 注: 6650是容器的PID
5、查看容器的DeviceName
＃ docker inspect --format='{ {.GraphDriver.Data.DeviceName}}' ac248a3c5c0e ####ac248a3c5c0e是容器ID docker-252:0-9700888-cc2ff9576cdf7736acca50ffdaadef471e01a8ffe9acb039c1d423edd941bd38
6、手动挂载
# mount /dev/mapper/docker-252\:0-9700888-cc2ff9576cdf7736acca50ffdaadef471e01a8ffe9acb039c1d423edd941bd38 -o rw,relatime,nouuid,attr2,inode64,sunit=512,swidth=1024,noquota -t xfs /var/lib/docker/devicemapper/mnt/cc2ff9576cdf7736acca50ffdaadef471e01a8ffe9acb039c1d423edd941bd38
７、退出
＃exit
8、再次执行docker-compose exec redis sh 无报错。
说明：此报错是由于mount挂载点丢失，具体原因目前还未知晓，若有知晓者欢迎告知！