我在virtualbox上安装了一个rex ray，配置使用官网生成的，然而在启动时它一直报同样的错误：

error: service startup failed: libstorage: error logging in

启动命令：rexray start
附上配置，使用这个网址：http://rexrayconfig.codedelle...

libstorage:
  service: virtualbox
virtualbox:
  endpoint: http://192.168.56.100:18083
  volumePath: /usrdata/Volumes
  controllerName: SATA

谷歌了半天，好像没有人像我这样直接死在开启服务上，附上debug信息

INFO[0000] configured default CSI module                 CSI_ENDPOINT=/run/docker/plugins/rexray.sock time=1514969505608
INFO[0000] DockerLegacyMode                              enabled=false time=1514969505608
DEBU[0000] trapped signals                               time=1514969505609
DEBU[0000] loading config                                buildType=client+agent+controller configFileName=rexray globalConfigFileExists=false globalConfigFilePath=/etc/rexray/rexray.yml ignoreExists=false time=1514969505609 userConfigFileExists=false userConfigFilePath=/root/.rexray/rexray.yml
DEBU[0000] cannot find global or user file               buildType=client+agent+controller configFileName=rexray globalConfigFileExists=false globalConfigFilePath=/etc/rexray/rexray.yml ignoreExists=false time=1514969505609 userConfigFileExists=false userConfigFilePath=/root/.rexray/rexray.yml
DEBU[0000] loading config                                buildType=client+agent+controller configFileName=config globalConfigFileExists=true globalConfigFilePath=/etc/rexray/config.yml ignoreExists=true time=1514969505609 userConfigFileExists=false userConfigFilePath=/root/.rexray/config.yml
DEBU[0000] disabled config file exist check              buildType=client+agent+controller configFileName=config globalConfigFileExists=true globalConfigFilePath=/etc/rexray/config.yml ignoreExists=true time=1514969505609 userConfigFileExists=false userConfigFilePath=/root/.rexray/config.yml
DEBU[0000] validating global config                      buildType=client+agent+controller configFileName=config globalConfigFileExists=true globalConfigFilePath=/etc/rexray/config.yml ignoreExists=true time=1514969505609 userConfigFileExists=false userConfigFilePath=/root/.rexray/config.yml
DEBU[0000] created new config                            buildType=client+agent+controller configFileName=config globalConfigFileExists=true globalConfigFilePath=/etc/rexray/config.yml ignoreExists=true time=1514969505610 userConfigFileExists=false userConfigFilePath=/root/.rexray/config.yml
DEBU[0000] initializing configuration                   
DEBU[0000] loading yaml for Global                      
DEBU[0000] loading yaml for CSI                         
DEBU[0000] loading global config file                    path=/etc/rexray/config.yml
DEBU[0000] usage template path                           path=/root/.rexray/usage.template time=1514969505613
DEBU[0000] loaded usage template                         source=UsageTemplate time=1514969505613
DEBU[0000] updating log level                            level=debug time=1514969505615
INFO[0000] updated log level                             logLevel=debug
DEBU[0000] os.args                                       time=1514969505620 val=[rexray -l debug start]
INFO[0000] created pid file                              path=/var/run/rexray/rexray.pid pid=3303 time=1514969505621
DEBU[0000] host is empty; initiliazing default services  time=1514969505634
INFO[0000] libStorage auto service mode enabled          driver=virtualbox time=1514969505639
DEBU[0000] starting embedded libStorage server           time=1514969505639
DEBU[0000] created scoped scope                          new=libstorage.server parentScopes=rexray,
INFO[0000] configured logging                            libstorage.logging.httpRequests=false libstorage.logging.httpResponses=false libstorage.logging.level=debug server=white-friend-mu time=1514969505692
DEBU[0000] parsed server auth property                   libstorage.server.auth.disabled=false server=white-friend-mu time=1514969505710
DEBU[0000] parsed server auth property                   libstorage.server.auth.key= server=white-friend-mu time=1514969505721
DEBU[0000] parsed server auth property                   libstorage.server.auth.alg=HS256 server=white-friend-mu time=1514969505728
DEBU[0000] parsed server auth property                   libstorage.server.auth.allow=[] server=white-friend-mu time=1514969505739
DEBU[0000] parsed server auth property                   libstorage.server.auth.deny=[] server=white-friend-mu time=1514969505748
INFO[0000] configured global auth                        libstorage.server.auth.alg=HS256 libstorage.server.auth.allow=[] libstorage.server.auth.deny=[] libstorage.server.auth.disabled=false libstorage.server.auth.key= server=white-friend-mu time=1514969505751
INFO[0000] initializing server                           server=white-friend-mu time=1514969505751
INFO[0000] initializing server services                  server=white-friend-mu time=1514969505751
DEBU[0000] configured result schema validation           enabled=false server=white-friend-mu time=1514969505755
DEBU[0000] got services map                              count=1 server=white-friend-mu time=1514969505758
DEBU[0000] processing service config                     server=white-friend-mu service=virtualbox time=1514969505758
DEBU[0000] getting scoped config for service             scope=libstorage.server.services.virtualbox server=white-friend-mu service=virtualbox time=1514969505758
DEBU[0000] created scoped scope                          new=libstorage.server.services.virtualbox parentScopes=libstorage.server,rexray,
DEBU[0000] got driver name                               driverName=virtualbox server=white-friend-mu service=virtualbox time=1514969505764
INFO[0000] initializing driver: map[moduleName:virtualbox userName: controllerName:SATA provider:virtualbox endpoint:http://192.168.56.100:18083 tls:false volumePath:/usrdata/Volumes machineNameOrId:]  server=white-friend-mu service=virtualbox storageDriver=virtualbox time=1514969505808
INFO[0000] service shutdown complete                     time=1514969505846
INFO[0000] removed pid file                              path=/var/run/rexray/rexray.pid time=1514969505847
error: service startup failed: libstorage: error logging in

另外，我在官网上注意到这段话：

...order to leverage the virtualbox driver, the libStorage client or must be located on each VM that you wish to be able to consume external volumes. The driver leverages the vboxwebserv HTTP SOAP API which is a process that must be started from the VirtualBox host (ie OS X) using vboxwebsrv -H 0.0.0.0 -v or additionally with -b for running in the background. This allows the VMs running libStorage to remotely make calls to the underlying VirtualBox application.

似乎就是要用vboxwebserv这个命令开启SOAP API，然而我还是没有找到相应的命令，最贴近的那个是个镜像……用在phpVirtualBox上（感觉不应该跟我有关系啊）

求各路大哥帮个忙解决下，谢谢。