如果在hbase的shell中输入了status报错，

hbase(main):001:0> status

ERROR: org.apache.hadoop.hbase.ipc.ServerNotRunningYetException: Server is not running yet
    at org.apache.hadoop.hbase.master.HMaster.checkServiceStarted(HMaster.java:2445)
    at org.apache.hadoop.hbase.master.MasterRpcServices.isMasterRunning(MasterRpcServices.java:946)
    at org.apache.hadoop.hbase.protobuf.generated.MasterProtos$MasterService$2.callBlockingMethod(MasterProtos.java:58521)
    at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2339)
    at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:123)
    at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:188)
    at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:168)

Here is some help for this command:
Show cluster status. Can be 'summary', 'simple', 'detailed', or 'replication'. The
default is 'summary'. Examples:

  hbase> 

然后网页出现了

解决：

关闭hdfs的安全模式，你也可以通过查看hadoop的50070端口的网站查看是否开启了安全模式

如何关闭安全模式？

hdfs dfsadmin -safemode leave

然后稍等几秒，再刷新网页就好了。