Out of Disk Space

Impact

The database may soon be unable to accept new writes.

Common Causes

• Increase in table/index disk space usage

  Some tables or indexes may be growing faster than expected. You can check the server-wide Schema statistics overview to see which databses are using the most disk space, and then check database-specific schema statistics to see which tables or indexes are taking the most space within that database.

• Temporary files

  If the Postgres temp_tablespaces setting is empty or set to a directory on the same partition as the data directory, you may have a long-running query using a lot of temporary files and consuming disk space. Canceling the query withpg_cancel_backend will release any temporary files and may reclaim some space.

Solution

Expanding storage and deleting data can both resolve this issue, though note that due to the MVCC mechanism Postgres uses, deleting data is unlikely to reclaim much space until you can run VACUUM FULL (which takes a full table lock (blocking all other queries) and has considerable disk space overhead while executing) or use pg_repack to reclaim disk space. Running TRUNCATE to purge all data from some tables may help.