4.2) SVRMGR> ORA-00445: background process "PMON" did not start after 120 seconds
SVRMGR> Server Manager complete.
5) when i came into office, did a grep ora and found no processes at all. had to manually shutdown oracle and then restart before they are fine. i did my own analysis and the closest i could get was that i had two entries in crontab which attepmted to start the database at the same time which is at 7am and could not find out anything. however, i wanted to know why the above errors occur.
1. The message regarding Crash Recovery in the Alert log because ur database was not shutdown properly. I think some body had sutdown the server before shutting down the database or database was shutdown abort. On restarting the database did auto recovery by appling redo logs.
2. for ORA-27100 error
as per oracle Documentation
ORA-27100 shared memory realm already exists
Cause: An attempt was made to start duplicate instances, or tried to restart an instance that had not been properly shut down.
Action: Use a different instance name, or cleanup the failed instance's SGA.