1）gentoo使用overlay安装docker，版本1.7.1
2）可以正常启动/etc/init.d/docker start
3)docker -d -D产生错误信息：

localhost ~ # docker -d -D
DEBU[0000] Registering GET, /images/{name:.*}/history
DEBU[0000] Registering GET, /containers/json
DEBU[0000] Registering GET, /containers/{name:.*}/export
DEBU[0000] Registering GET, /containers/{name:.*}/json
DEBU[0000] Registering GET, /events
DEBU[0000] Registering GET, /images/search
DEBU[0000] Registering GET, /images/get
DEBU[0000] Registering GET, /images/{name:.*}/get
DEBU[0000] Registering GET, /exec/{id:.*}/json
DEBU[0000] Registering GET, /info
DEBU[0000] Registering GET, /containers/{name:.*}/top
DEBU[0000] Registering GET, /containers/{name:.*}/logs
DEBU[0000] Registering GET, /containers/{name:.*}/stats
DEBU[0000] Registering GET, /_ping
DEBU[0000] Registering GET, /images/json
DEBU[0000] Registering GET, /images/{name:.*}/json
DEBU[0000] Registering GET, /containers/{name:.*}/attach/ws
DEBU[0000] Registering GET, /version
DEBU[0000] Registering GET, /containers/ps
DEBU[0000] Registering GET, /containers/{name:.*}/changes
DEBU[0000] Registering POST, /commit
DEBU[0000] Registering POST, /images/create
DEBU[0000] Registering POST, /images/load
DEBU[0000] Registering POST, /images/{name:.*}/push
DEBU[0000] Registering POST, /images/{name:.*}/tag
DEBU[0000] Registering POST, /containers/{name:.*}/pause
DEBU[0000] Registering POST, /containers/{name:.*}/rename
DEBU[0000] Registering POST, /containers/{name:.*}/unpause
DEBU[0000] Registering POST, /containers/{name:.*}/restart
DEBU[0000] Registering POST, /exec/{name:.*}/resize
DEBU[0000] Registering POST, /containers/create
DEBU[0000] Registering POST, /containers/{name:.*}/kill
DEBU[0000] Registering POST, /containers/{name:.*}/start
DEBU[0000] Registering POST, /containers/{name:.*}/stop
DEBU[0000] Registering POST, /containers/{name:.*}/resize
DEBU[0000] Registering POST, /auth
DEBU[0000] Registering POST, /build
DEBU[0000] Registering POST, /containers/{name:.*}/wait
DEBU[0000] Registering POST, /containers/{name:.*}/attach
DEBU[0000] Registering POST, /containers/{name:.*}/copy
DEBU[0000] Registering POST, /containers/{name:.*}/exec
DEBU[0000] Registering POST, /exec/{name:.*}/start
DEBU[0000] Registering DELETE, /containers/{name:.*}
DEBU[0000] Registering DELETE, /images/{name:.*}
DEBU[0000] Registering OPTIONS,
DEBU[0000] [zfs] no zfs dataset found for rootdir '/var/lib/docker'
DEBU[0000] devicemapper: driver version is 4.30.0
DEBU[0000] Generated prefix: docker-8:4-56098982
DEBU[0000] Checking for existence of the pool 'docker-8:4-56098982-pool'
DEBU[0000] Pool doesn't exist. Creating it.
DEBU[0000] Creating loopback file /var/lib/docker/devicemapper/devicemapper/data for device-manage use
DEBU[0000] Creating loopback file /var/lib/docker/devicemapper/devicemapper/metadata for device-manage use
FATA[0000] Error starting daemon: error initializing graphdriver: Error running DeviceCreate (CreatePool) dm_task_run failed

4）使用在github上面的issue里面提供的脚本，配置信息如下：

localhost ~ # ./check-config.sh
warning: /proc/config.gz does not exist, searching other paths for kernel config ...
info: reading kernel config from /boot/config-4.0.5-gentoo ...

Generally Necessary:

• cgroup hierarchy: properly mounted [/sys/fs/cgroup]

• CONFIG_NAMESPACES: enabled

• CONFIG_NET_NS: enabled

• CONFIG_PID_NS: enabled

• CONFIG_IPC_NS: enabled

• CONFIG_UTS_NS: enabled

• CONFIG_DEVPTS_MULTIPLE_INSTANCES: enabled

• CONFIG_CGROUPS: enabled

• CONFIG_CGROUP_CPUACCT: enabled

• CONFIG_CGROUP_DEVICE: enabled

• CONFIG_CGROUP_FREEZER: enabled

• CONFIG_CGROUP_SCHED: enabled

• CONFIG_CPUSETS: enabled

• CONFIG_MEMCG: enabled

• CONFIG_MACVLAN: enabled

• CONFIG_VETH: enabled

• CONFIG_BRIDGE: enabled

• CONFIG_BRIDGE_NETFILTER: enabled

• CONFIG_NF_NAT_IPV4: enabled

• CONFIG_IP_NF_FILTER: enabled

• CONFIG_IP_NF_TARGET_MASQUERADE: enabled

• CONFIG_NETFILTER_XT_MATCH_ADDRTYPE: enabled

• CONFIG_NETFILTER_XT_MATCH_CONNTRACK: enabled

• CONFIG_NF_NAT: enabled

• CONFIG_NF_NAT_NEEDED: enabled

• CONFIG_POSIX_MQUEUE: enabled

Optional Features:

• CONFIG_USER_NS: missing

• CONFIG_SECCOMP: enabled

• CONFIG_MEMCG_KMEM: missing

• CONFIG_MEMCG_SWAP: enabled

• CONFIG_MEMCG_SWAP_ENABLED: enabled

• CONFIG_BLK_CGROUP: enabled

• CONFIG_IOSCHED_CFQ: enabled

• CONFIG_BLK_DEV_THROTTLING: missing

• CONFIG_CGROUP_PERF: enabled

• CONFIG_CGROUP_HUGETLB: missing

• CONFIG_NET_CLS_CGROUP: missing

• CONFIG_CGROUP_NET_PRIO: missing

• CONFIG_CFS_BANDWIDTH: enabled

• CONFIG_FAIR_GROUP_SCHED: enabled

• CONFIG_RT_GROUP_SCHED: missing

• CONFIG_EXT3_FS: enabled

• CONFIG_EXT3_FS_XATTR: enabled

• CONFIG_EXT3_FS_POSIX_ACL: missing

• CONFIG_EXT3_FS_SECURITY: missing
  (enable these ext3 configs if you are using ext3 as backing filesystem)

• CONFIG_EXT4_FS: enabled

• CONFIG_EXT4_FS_POSIX_ACL: enabled

• CONFIG_EXT4_FS_SECURITY: enabled

• Storage Drivers:

  • "aufs":

    • CONFIG_AUFS_FS: missing

  • "btrfs":

    • CONFIG_BTRFS_FS: enabled

  • "devicemapper":

    • CONFIG_BLK_DEV_DM: enabled

    • CONFIG_DM_THIN_PROVISIONING: enabled

  • "overlay":

    • CONFIG_OVERLAY_FS: missing

  • "zfs":

    • /dev/zfs: missing

    • zfs command: missing

    • zpool command: missing

5)uname -a:
Linux localhost 4.0.5-gentoo #1 SMP Sat Jul 11 10:23:15 CST 2015 x86_64 Intel(R) Celeron(R) CPU N2830 @ 2.16GHz GenuineIntel GNU/Linux

6)docker version:
localhost ~ # docker version
Client version: 1.7.1
Client API version: 1.19
Go version (client): go1.4.2
Git commit (client): 786b29d
OS/Arch (client): linux/amd64
Cannot connect to the Docker daemon. Is 'docker -d' running on this host?

7）尝试改用localhost ~ # docker -d --storage-driver=btrfs：
FATA[0000] Error starting daemon: error initializing graphdriver: driver not supported