ORA-01012: not logged on startup failed

DB startup failed with error: ORA-01012: not logged on

Background:
==============
Database is taking more time to stop say almost one hour and its hung so killed background process using below command

$ kill -9 <PID>

OR

$kill -9 -1



Problem:
==========
Now while starting the DB instance.

$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Tue Sep 25 07:23:45 2018

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected.

SQL> startup

ORA-01012: not logged on

SQL> conn / as sysdba

Connected to an idle instance.

SQL> startup

ORA-01012: not logged on

So whenever we forcefully shut down the DB this issue may occurs

“SYSRESV”  shows a shared memory segment for a non-existing instance



Solution:
=======

At OS level remove the orphaned shared memory segment using this utility

$ sysresv

IPC Resources for ORACLE_SID “SID” :

Shared Memory:

ID              KEY

11345673         0xffffffff

46               0xffffffff

59               0x6767020c

Oracle Instance not alive for sid “SID”

$ ipcrm -m 11345673

$ ipcrm -m 46

$ ipcrm -m 59



Now tried to start DB

$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Tue Sep 25 07:29:17 2018

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup

ORACLE instance started.

Total System Global Area 7482626048 bytes

Fixed Size                  2236048 bytes

Variable Size            3271557488 bytes

Database Buffers         4194304000 bytes

Redo Buffers               14528512 bytes

Database mounted.

Database opened.

SQL>