RDS Oracle storage allocated larger than source instance


Hello We have an oracle rds source instance with 5 read only replicas. The source and four replicas have about 4000 GB allocated storage, a fifth one exceeds 8000 GB and seems to be growing up. The datafiles, tempfiles, are obviously the same. How can I check the detail usage ? Thanks

4 Answers


It sounds like you're observing unexpected storage behavior with one of your Oracle RDS read replicas. Connect to the problematic read replica using an SQL client and execute the following query to check the size of each tablespace and its datafiles:

    df.tablespace_name "Tablespace",
    ROUND(SUM(df.bytes) / 1024 / 1024) "Size (MB)",
    ROUND(MAX(df.bytes) / 1024 / 1024) "Max Datafile Size (MB)"
    dba_data_files df

Check for Backups and Snapshots: It's possible that backups or snapshots are consuming additional storage. Check the "Automated Backups" and "Snapshots" sections in the RDS dashboard for this replica.

Best regards, Andrii

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answered 6 months ago

Hello Andrii

It seems that datafiles are ok. I also run the commands to crosscheck the archives, and clear the bdump folder, and near 5 TB has been cleared. I think an application generates a lot of trace files. I set their retention to a minimum.

Thank you.

answered 6 months ago

Could you please accept the answer if it helped for you? Regards, Andrii

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answered 6 months ago


I am glad that by clearing the trace files you were able to reclaim the storage back. Trace and dump files can accumulate and consume disk space. By default, Amazon RDS purges trace and dump files that are older than seven days. You can always change the retention period to avoid high disk usage.

Kindly let me know if you have any other doubt/query.

Thanks and Regards, Nishant Kumar

answered 6 months ago

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