今天在搭建集群的时候给HDFS添加角色的时候，出现了 NFS Gateway 一直启动失败，具体的错误如下：
using as SECURE_USER using as SECURE_GROUP CONF_DIR=/var/run/cloudera-scm-agent/process/78-hdfs-NFSGATEWAY CMF_CONF_DIR=/etc/cloudera-scm-agent unlimited Cannot connect to port 111. No portmap or rpcbind service is running on this host. Please start portmap or rpcbind service before attempting to start the NFS Gateway role on this host. Tue Dec 4 10:25:43 CST 2018 JAVA_HOME=/usr/java/jdk1.7.0_67-cloudera using /usr/java/jdk1.7.0_67-cloudera as JAVA_HOME using 5 as CDH_VERSION using /var/run/cloudera-scm-agent/process/78-hdfs-NFSGATEWAY as CONF_DIR using as SECURE_USER using as SECURE_GROUP CONF_DIR=/var/run/cloudera-scm-agent/process/78-hdfs-NFSGATEWAY CMF_CONF_DIR=/etc/cloudera-scm-agent unlimited Cannot connect to port 111. No portmap or rpcbind service is running on this host. Please start portmap or rpcbind service before attempting to start the NFS Gateway role on this host. Tue Dec 4 10:25:45 CST 2018 JAVA_HOME=/usr/java/jdk1.7.0_67-cloudera using /usr/java/jdk1.7.0_67-cloudera as JAVA_HOME using 5 as CDH_VERSION using /var/run/cloudera-scm-agent/process/78-hdfs-NFSGATEWAY as CONF_DIR using as SECURE_USER using as SECURE_GROUP CONF_DIR=/var/run/cloudera-scm-agent/process/78-hdfs-NFSGATEWAY CMF_CONF_DIR=/etc/cloudera-scm-agent unlimited
具体的错误如下No portmap or rpcbind service is running on this host. Please start portmap or rpcbind service before attempting to start the NFS Gateway role on this host.
这个问题是 portmap or rpcbind服务没有启动导致的：
解决办法如下：
HDFS NFS Gateway工作需要依附 rpcbind 服务，所以启动前需要确定rpcbind服务正常开启。 service rpcbind start （在添加服务的机器上面都需要执行）
但是HDFS NFS 服务会与系统自带的NFS服务冲突，所以在启动前需要关闭系统自带的NFS服务。service nfs stop （这个服务没有就不管他）
开启服务然后再添加服务启动服务：
至此服务启动成功
参考文档如下：
https://blog.csdn.net/ashic/article/details/79459048
https://cloud.tencent.com/developer/article/1189360