Description of problem:
The docker daemon is run in a shared mount namespace, causing problems when restarting the docker service. This prevents starting up containers where mounts remain in place.

Version-Release number of selected component (if applicable):
1.5.0-1.el6

How reproducible:
Always

Steps to Reproduce:
1. docker run -d --name test centos sleep infinity
2. service docker restart
3. docker start test

Actual results:
Error response from daemon: Cannot start container test: Error getting container 0412d5cce356ff269bd85b2096eb8bc0b2cc58a67096c6c6587a85f7e82f0b77 from driver devicemapper: Error mounting '/dev/mapper/docker-253:0-2097716-0412d5cce356ff269bd85b2096eb8bc0b2cc58a67096c6c6587a85f7e82f0b77' on '/var/lib/docker/devicemapper/mnt/0412d5cce356ff269bd85b2096eb8bc0b2cc58a67096c6c6587a85f7e82f0b77': device or resource busy
FATA[0000] Error: failed to start one or more containers

Expected results:
Container to start.

Additional info:
A merged pull request containing updated sysvinit script is found here: https://github.com/docker/docker/pull/10225

It was merged prior to the 1.5.0 release and involves running "unshare -m" when starting the docker daemon to place it into its own mount namespace.