For now, docker stats appears to be libcontainer only

Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au>

docs/man/docker-stats.1.md

@@ -13,6 +13,8 @@ docker-stats - Display a live stream of one or more containers' resource usage s
 
 Display a live stream of one or more containers' resource usage statistics
 
+Note: this functionality currently only works when using the *libcontainer* exec-driver.
+
 # OPTIONS
 **--help**
   Print usage statement

docs/sources/reference/api/docker_remote_api.md

@@ -73,6 +73,8 @@ root filesystem as read only.
 **New!**
 This endpoint returns a live stream of a container's resource usage statistics.
 
+> **Note**: this functionality currently only works when using the *libcontainer* exec-driver.
+
 
 ## v1.16
 

docs/sources/reference/api/docker_remote_api_v1.17.md

@@ -523,6 +523,8 @@ Status Codes:
 
 This endpoint returns a live stream of a container's resource usage statistics.
 
+> **Note**: this functionality currently only works when using the *libcontainer* exec-driver.
+
 **Example request**:
 
         GET /containers/redis1/stats HTTP/1.1

docs/sources/reference/commandline/cli.md

@@ -2004,6 +2004,8 @@ more details on finding shared images from the command line.
 
       --help=false       Print usage
 
+> **Note**: this functionality currently only works when using the *libcontainer* exec-driver.
+
 Running `docker stats` on multiple containers
 
     $ sudo docker stats redis1 redis2