系统环境：
win10 + virtualbox5.0.24
docker,docker-machine版本

JYC103@Fanne MINGW64 ~
$ docker-machine.exe -version
docker-machine.exe version 0.7.0, build a650a40

JYC103@Fanne MINGW64 ~
$ docker version
Client:
 Version:      1.12.0
 API version:  1.24
 Go version:   go1.6.3
 Git commit:   8eab29e
 Built:        Thu Jul 28 23:54:00 2016
 OS/Arch:      windows/amd64
An error occurred trying to connect: Get http://%2F%2F.%2Fpipe%2Fdocker_engine/v1.24/version: open //./pipe/docker_engine: The system cannot find the file specified.

现在docker-machine上有一台docker主机

$ docker-machine.exe ls
NAME            ACTIVE   DRIVER      STATE     URL                         SWARM   DOCKER    ERRORS
docker.20.127   -        none        Running   tcp://192.168.20.127:2375           Unknown   Unable to query docker version: Unable to read TLS config: open C:\Users\JYC103\.docker\machine\machines\docker.20.127\server.pem: The system cannot find the file specified.

直接docker info 这台docker主机

$ docker -H 192.168.20.127:2375 info
Containers: 0
 Running: 0
 Paused: 0
 Stopped: 0
Images: 0
Server Version: 1.12.0
Storage Driver: devicemapper
 Pool Name: docker-253:1-101251423-pool
 Pool Blocksize: 65.54 kB
 Base Device Size: 10.74 GB
 Backing Filesystem: xfs
 Data file: /dev/loop0
 Metadata file: /dev/loop1
 Data Space Used: 11.73 MB
 Data Space Total: 107.4 GB
 Data Space Available: 14.84 GB
 Metadata Space Used: 581.6 kB
 Metadata Space Total: 2.147 GB
 Metadata Space Available: 2.147 GB
 Thin Pool Minimum Free Space: 10.74 GB
 Udev Sync Supported: true
 Deferred Removal Enabled: false
 Deferred Deletion Enabled: false
 Deferred Deleted Device Count: 0
 Data loop file: /var/lib/docker/devicemapper/devicemapper/data
 WARNING: Usage of loopback devices is strongly discouraged for production use. Use `--storage-opt dm.thinpooldev` to specify a custom block storage device.
 Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
 Library Version: 1.02.107-RHEL7 (2016-06-09)
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: null host bridge overlay
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Security Options: seccomp
Kernel Version: 3.10.0-123.el7.x86_64
Operating System: CentOS Linux 7 (Core)
OSType: linux
Architecture: x86_64
CPUs: 1
Total Memory: 987.2 MiB
Name: localhost.localdomain
ID: FMPB:NCHQ:ERTQ:YQMK:WUSA:QA2T:FCQO:TL7L:IHOH:3Z3Z:EXTV:3YMY
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
Insecure Registries:
 127.0.0.0/8

问题开始了
现在要docker-machine env查看一下docke.20.127主机的变量，出现以下提示

$ docker-machine.exe env docker.20.127
Error checking TLS connection: Error checking and/or regenerating the certs: There was an error validating certificates for host "192.168.20.127:2375": open C:\Users\JYC103\.docker\machine\machines\docker.20.127\server.pem: The system cannot find the file specified.
You can attempt to regenerate them using 'docker-machine regenerate-certs [name]'.
Be advised that this will trigger a Docker daemon restart which will stop running containers.

server.pem不存在，按照它的提示创建一个

$ docker-machine.exe regenerate-certs docker.20.127
Regenerate TLS machine certs?  Warning: this is irreversible. (y/n): y
Regenerating TLS certificates
Waiting for SSH to be available...
Too many retries waiting for SSH to be available.  Last error: Maximum number of retries (60) exceeded

但是等了几分钟后，没创建成功，打开debug调试

$ docker-machine.exe -D regenerate-certs docker.20.127
Docker Machine Version:  0.7.0, build a650a40
Regenerate TLS machine certs?  Warning: this is irreversible. (y/n): y
Regenerating TLS certificates
Found binary path at C:\Users\JYC103\bin\docker-machine.exe
Launching plugin server for driver none
Plugin server listening at address 127.0.0.1:58959
() Calling .GetVersion
Using API Version  1
() Calling .SetConfigRaw
() Calling .GetMachineName
command=configureAuth machine=docker.20.127
Waiting for SSH to be available...
Getting to WaitForSSH function...
(docker.20.127) Calling .GetSSHHostname
(docker.20.127) Calling .GetSSHPort
(docker.20.127) Calling .GetSSHKeyPath
(docker.20.127) Calling .GetSSHUsername
Using SSH client type: external
&{[-F /dev/null -o BatchMode=yes -o PasswordAuthentication=no -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=quiet -o ConnectionAttempts=3 -o ConnectTimeout=10 -o ControlMaster=no -o ControlPath=none @ -p 0] C:\Program Files\Git\usr\bin\ssh.exe <nil>}
About to run SSH command:
exit 0
SSH cmd err, output: exit status 255: usage: ssh [-1246AaCfGgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]
           [-D [bind_address:]port] [-E log_file] [-e escape_char]
           [-F configfile] [-I pkcs11] [-i identity_file]
           [-L address] [-l login_name] [-m mac_spec]
           [-O ctl_cmd] [-o option] [-p port]
           [-Q cipher | cipher-auth | mac | kex | key]
           [-R address] [-S ctl_path] [-W host:port]
           [-w local_tun[:remote_tun]] [user@]hostname [command]

Error getting ssh command 'exit 0' : Something went wrong running an SSH command!
command : exit 0
err     : exit status 255
output  : usage: ssh [-1246AaCfGgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]
           [-D [bind_address:]port] [-E log_file] [-e escape_char]
           [-F configfile] [-I pkcs11] [-i identity_file]
           [-L address] [-l login_name] [-m mac_spec]
           [-O ctl_cmd] [-o option] [-p port]
           [-Q cipher | cipher-auth | mac | kex | key]
           [-R address] [-S ctl_path] [-W host:port]
           [-w local_tun[:remote_tun]] [user@]hostname [command]

报ssh链接错误。
这问题要如何解决，要如何才能生成server.pem这个文件的？