ORA-27101 ORA-01034 troubleshooting

Oracle has been started. After connecting to sqlplus, perform the query. the following error occurs:
 
A ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory
SQL> shutdown immediate;
A ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
 
Linux-x86_64 Error: 2: No such file or directory
 
Think of the oracle user's environment variable that has just been modified. It should be that oracle_home cannot be found and modified again. It is normal.

Recommended reading:

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