Increase space for VFS storage driver

Hello,

I have a Redhat 7.0 machine with latest docker 1.11.

docker info

Containers: 1
Running: 0
Paused: 0
Stopped: 1
Images: 3
Server Version: 1.11.2
Storage Driver: vfs
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins: 
 Volume: local
 Network: host bridge null
Kernel Version: 3.10.0-123.8.1.el7.x86_64
Operating System: Red Hat Enterprise Linux Server 7.0 (Maipo)
OSType: linux
Architecture: x86_64
CPUs: 2
Total Memory: 7.641 GiB
Docker Root Dir: /var/lib/docker
Debug mode (client): false
Debug mode (server): true
 File Descriptors: 14
 Goroutines: 29
 EventsListeners: 0
Registry: https://index.docker.io/v1/

uname -a

Linux 3.10.0-123.8.1.el7.x86_64 #1 SMP Mon Aug 11 13:37:49 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux

I use binary version, and run it as root with cmd:

/usr/bin/docker daemon --debug

This is the logs

WARN[0000] containerd: low RLIMIT_NOFILE changing to max current=1024 max=4096
DEBU[0000] containerd: read past events count=0
DEBU[0000] containerd: supervisor running cpus=2 memory=7824 runtime=docker-runc runtimeArgs= stateDir=/run/containerd
DEBU[0000] containerd: grpc api on /var/run/docker/libcontainerd/docker-containerd.sock
DEBU[0001] Using default logging driver json-file
DEBU[0001] Golang’s threads limit set to 112230
DEBU[0001] received past containerd event: &types.Event{Type:“live”, Id:“”, Status:0x0, Pid:“”, Timestamp:0x575a864f}
DEBU[0001] [zfs] zfs command is not available: exec: “zfs”: executable file not found in $PATH
DEBU[0001] devicemapper: driver version is 4.27.0
ERRO[0001] devmapper: Udev sync is not supported. This will lead to data loss and unexpected behavior. Install a dynamic binary to use devicemapper or select a different storage driver. For more information, see https://docs.docker.com/engine/reference/commandline/daemon/#daemon-storage-driver-option
ERRO[0001] ‘overlay’ not found as a supported filesystem on this host. Please ensure kernel is new enough and has overlay support loaded.
DEBU[0001] Using graph driver vfs

when I’ll try to pull a new image, for example

docker pull jenkinsci/slave

I have this output

failed to register layer: Untar re-exec error: exit status 1: output: open /usr/share/perl/5.20.2/Test/Builder.pm: no space left on device

How can I add more space to driver? I found only tips for devicemapper type.

Can anyone help me?

Thanks

Is a cloud service used for Docker? If so, which one?
For Amazon EC2 expand the volume.
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-expand-volume.html

Yes, it is a EC2 instance, but I cannot modify volume or partitioning.
Why if I have 40GB of disk, the maximum size of /var/lib/docker/vfs is 3.6GB?

Has all feasible free space been freed? Remove containers and Docker images not being used.