一．启动hadoop后运行hive时出现如下错误。

     Exception in thread "main" java.lang.RuntimeException: java.lang.RuntimeException: The root scratch dir: /tmp/hive on HDFS should be writable.
     Current permissions are: rwxr-xr-x

        at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:522)

        at org.apache.hadoop.hive.cli.CliDriver.run(CliDriver.java:677)

        at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:621)

        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

        at java.lang.reflect.Method.invoke(Method.java:606)

        at org.apache.hadoop.util.RunJar.main(RunJar.java:212)

        Caused by: java.lang.RuntimeException: The root scratch dir: /tmp/hive on HDFS should be writable. Current permissions are: rwxr-xr-x

        at org.apache.hadoop.hive.ql.session.SessionState.createRootHDFSDir(SessionState.java:612)

        at org.apache.hadoop.hive.ql.session.SessionState.createSessionDirs(SessionState.java:554)

        at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:508)

        ... 7 more

二．错误分析。

从The root scratch dir: /tmp/hive on HDFS should be writable. Current permissions are: rwxr-xr-x可以看出。系统要求在hdfs上用户应该具备写权限，而从报错可以看出只有所有者具有写权限，所有组合其他用户不具备。

三．错误修改。

使用hadoop fs hadoop fs -chmod -R dir修改目录权限，如下

[root@hadoop22 ~]# hadoop fs -chmod -R 777 /tmp