Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options
Starting "SYSTEM"."SYS_EXPORT_SCHEMA_01":  system/******** schemas=test directory=expdp_dir dumpfile=test_%u.dmp filesize=10g parallel=4 logfile=expdpfull.log
Estimate in progress using BLOCKS method...
Processing object type SCHEMA_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 32.85 GB
Processing object type SCHEMA_EXPORT/USER
Processing object type SCHEMA_EXPORT/SYSTEM_GRANT
Processing object type SCHEMA_EXPORT/ROLE_GRANT
Processing object type SCHEMA_EXPORT/DEFAULT_ROLE
Processing object type SCHEMA_EXPORT/PRE_SCHEMA/PROCACT_SCHEMA
Processing object type SCHEMA_EXPORT/SYNONYM/SYNONYM
Processing object type SCHEMA_EXPORT/SEQUENCE/SEQUENCE
Processing object type SCHEMA_EXPORT/TABLE/TABLE
ORA-31693: Table data object "test"."WF_HIST" failed to load/unload and is being skipped due to error:
ORA-31617: unable to open dump file "/home/oracle/dump/test_03.dmp" for write
ORA-19505: failed to identify file "/home/oracle/dump/test_03.dmp"
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3

原因和解决方法：
在rac环境使用并行导出时，系统会尝试同时写文件到rac中的节点。如果导出目录是本地磁盘的话，导出时候就会报错，出现上面的现象。

解决方法：导出的时候添加参数cluster=no

例如：

expdp \'sys/oracle as sysdba\' DIRECTORY=backup_exp_dir DUMPFILE=$v_date.dmp LOGFILE=$v_date.log SCHEMAS=你的schemas parallel=2 cluster=N