按照运行HIVE报错

昨日刚把HIVE安装好，今天开始运行hive的时候报错如下：

ERROR XBM0H: Directory /root/metastore_db cannot be created.
        at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
        at org.apache.derby.impl.services.monitor.StorageFactoryService$9.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.apache.derby.impl.services.monitor.StorageFactoryService.createServiceRoot(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.bootService(Unknown Source)
        at org.apache.derby.impl.services.monitor.BaseMonitor.createPersistentService(Unknown Source)
        at org.apache.derby.iapi.services.monitor.Monitor.createPersistentService(Unknown Source)
        at org.apache.derby.impl.jdbc.EmbedConnection.createDatabase(Unknown Source)
        at org.apache.derby.impl.jdbc.EmbedConnection.(Unknown Source)
        at org.apache.derby.impl.jdbc.EmbedConnection30.(Unknown Source)
        at org.apache.derby.impl.jdbc.EmbedConnection40.(Unknown Source)
        at org.apache.derby.jdbc.Driver40.getNewEmbedConnection(Unknown Source)
        at org.apache.derby.jdbc.InternalDriver.connect(Unknown Source)
        at org.apache.derby.jdbc.AutoloadedDriver.connect(Unknown Source)
        at java.sql.DriverManager.getConnection(DriverManager.java:582)
        at java.sql.DriverManager.getConnection(DriverManager.java:185)
        at org.apache.commons.dbcp.DriverManagerConnectionFactory.createConnection(DriverManagerConnectionFactory.java:75)
        at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582)
        at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:1148)
        at org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:106)
        at org.datanucleus.store.rdbms.ConnectionFactoryImpl$ManagedConnectionImpl.getConnection(ConnectionFactoryImpl.java:521)
        at org.datanucleus.store.rdbms.RDBMSStoreManager.(RDBMSStoreManager.java:290)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)

        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)

我仔细分析原因是我启动的目录是/root下所以我的hadoop用户没有权限，导致建立数据库文件有问题。于是我将启动的目录切换到hive的安装目录下面，可以正常启动。