ORA-01034: ORACLE not available ORA-27101: shared memory realm does not exist

Question

I am getting the above error when trying to connect to a server database from a client using service name orcl. It is getting connected when I am using the other service name i.e. dms

Below is my listener.ora

SID_LIST_LISTENER =   (SID_LIST =     (SID_DESC =       (SID_NAME = dms)       (SERVICE_NAME = dms)       (ORACLE_HOME = /home/oracle/app/oracle/product/11.2.0/dbhome_1) #      (PROGRAM = extproc)     )   (SID_DESC =      (SID_NAME = orcl)      (SERVICE_NAME = dms)     # (GLOBAL_DBANME = orcl)       (ORACLE_HOME = /home/oracle/app/oracle/product/11.2.0/dbhome_1)    #  (PROGRAM = extproc)   )   )   LISTENER =   (DESCRIPTION_LIST =     (DESCRIPTION =       (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))       (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.53)(PORT = 1521))      )   )  ADR_BASE_LISTENER = /home/oracle/app/oracle and tnsnames.ora ORCL =   (DESCRIPTION =     (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.53)(PORT = 1521))     (CONNECT_DATA =       (SERVER = DEDICATED)      #(SERVICE_NAME = orcl.localdomain)       (ORACLE_SID = dms)       (SERVICE_NAME = orcl)     )   )  DMS =   (DESCRIPTION =     (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.53)(PORT = 1521))     (CONNECT_DATA =       (SERVER = DEDICATED)       (SERVICE_NAME = dms)       (ORACLE_SID = dms)     )   ) 

Please tell me what to do?

Answer 1

Open command prompt and execute the below commands:

set oracle_sid=DATABASE NAME sqlplus /nolog conn sys/sys as sysdba shutdown abort startup 

Answer 2

Sometimes, the database will not be mounted correctly, so we need to mount it manually. For that, shut it down and start it up then mount. Log in as oracle user, then run the following commands:

sqlplus / as sysdba; shutdown immediate; startup nomount; alter database mount; alter database open;