ORACLE数据库报错ORA-01034

在使用expdp 导出数据表时报错：

sqlplus sys/sys as sysdba

create directory exp_dir as '/home/oracle/backup';
grant read,write on directory exp_dir to public;

[oracle@oracle-01 ~]$ expdp sys/sys@p012band tables=fnsonlp.facd file=limit_facitity_20180425.dmp directory=exp_dir logfile=limit_20180425.log

Export: Release 11.2.0.4.0 - Production on Wed Apr 25 20:42:14 2018


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UDE-28009: operation generated ORACLE error 28009
ORA-28009: connection as SYS should be as SYSDBA or SYSOPER


Username: sys/sys as sysdba


UDE-01034: operation generated ORACLE error 1034
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory

UDE-00003: all allowable logon attempts failed

问题找到了，输入用户时没有指定实例名

sys/sys@p012band as sysdba