PowerProtect Data Manager: PostgreSQL backup fails due to /tmp disk space exhaustion when using Default pg_dump script

PPDM protects a PostgreSQL database using the Generic Application Agent with the default pg_dump backup script. Backups fail due to insufficient disk space. The /tmp filesystem on the agent host fills to capacity during the backup operation. Smaller databases may back up successfully while larger databases that exceed the available /tmp space consistently fail.

The default parameters used in the provided script use /tmp as a staging area before writing the backup to Data Domain.

1. Upgrade the PPDM appliance to version 20.1.0.0-14 or later. Download the latest release from the PowerProtect Data Manager Drivers & Downloads page.
2. Modify the Default Backup Script:
   • In the PPDM UI, navigate to Protection → Scripts.
   • Locate the PostgreSQL backup script.
   • Edit the script and find the pg_dump command line containing the -F t parameter:
   • Original:

     echo "Starting pg_dump for database $db PG_DUMPBACKUP_PATH: $PG_DUMPBACKUP_PATH"
           output=$("${PG_DUMPBACKUP_PATH}" "${port_option}" -F t -f "${base_backup_dir}/${db}-$(date +%Y%m%d-%H%M%S).tar" ${username} "${db}")

   • Change the -F t parameter to -F c -Z 0:
   • Updated:

     echo "Starting pg_dump for database $db PG_DUMPBACKUP_PATH: $PG_DUMPBACKUP_PATH"
           output=$("${PG_DUMPBACKUP_PATH}" "${port_option}" -F c -Z 0 -f "${base_backup_dir}/${db}-$(date +%Y%m%d-%H%M%S).tar" ${username} "${db}")

   • Save the script.
3. Verify the Fix
   • Run a manual PostgreSQL backup from PPDM for the affected database.
   • Confirm the backup completes successfully without /tmp space exhaustion.
   • Monitor the /tmp filesystem during the backup and confirm it does not fill to capacity.
4. If PostgreSQL backups continue to fail after modifying the script parameters, contact Dell Support for additional investigation and reference this KB article.