Solve Connect to Idle Instance problems Step 1 View the Oracle_SID. [oracle@linuxserver ~]$ echo $ORACLE_SID cjdl SID = spfilecjdl.ora = spfilecjdl.ora = spfilecjdl.ora = spfilecjdl.ora = spfilecjdl.ora = spfilecjdl.ora = spfilecjdl.ora [oracle@linuxserver ~]$ cd $ORACLE_HOME [oracle@linuxserver 11.2.0]$ cd dbs [oracle@linuxserver dbs]$ ls hc_cjdl.dat hc_DBUA0.dat init.ora lkCJDL orapwcjdl spfilecjdl.ora Most of the time, it’s because something went wrong here. Step 2 [oracle@linuxserver dbs]$ export ORACLE_SID=cjdl Generally speaking, export1 can be normally connected. Step 3 [oracle@linuxserver dbs]$ sqlplus / as sysdba Ok! Normal connection.