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Oracle Troubleshooting

ORA-01102: cannot mount database in exclusive mode

Symptom:

When opening or mounting the database, the following error is generated:

ORA-01102: cannot mount database in EXCLUSIVE mode.

Cause:

I have only come across this error when using Oracle Parallel Server (OPS). Here, this error indicates that another instance has already been mounted in exclusive or parallel mode.

Possibly Remedies:

• Mount the database in parallel mode.

• Shutdown all other instances before mounting the database in exclusive mode.

• Try stopping and then restarting the service 'OracleService<SID>'.