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RDS for PostgreSQL

WAL management

Configuring local remaining available space protection

This topic describes how to configure local remaining available space protection in the console.

Background information

RDS for PostgreSQL supports local remaining available space protection. after enabling this feature, the instance automatically clears the earliest local WAL log when storage usage exceeds 80% or remaining space is less than 5 GB, until usage drops below 80% and remaining space exceeds 5 GB, preventing abnormalities such as instance read-only due to high storage usage.

Precautions

After enabling local remaining available space protection, the instance clears WAL logs in chronological order from oldest to recent. After clearing the WAL, there might be issues such as the range of selectable time for instance point-in-time recovery having discontinuities, and logical replication slots becoming invalid. Proceed with caution.

Due to active logical replication slots not consuming in time, WAL logs may not be cleared promptly, causing storage space to not be released timely. If storage usage remains high for a long time after enabling this feature, monitor the accumulation of WAL logs in the instance's logical replication slots. For more details on clearing logical replication slots, refer to How to troubleshoot and handle inactive logical replication slots in instances.

Prerequisites

An instance is created and in the Running state. For more details, refer to Creating an instance.

Procedure

In the upper-left corner of the top menu bar, select the project and region for the instance.

tip

If the project of the instance has not been set, the project should be selected as All resources.

Click on Instances in the left navigation bar.

On the Instances page, click on the target instance name.

At the top of the page, click Backups.

In the Backups tab, click the WAL management sub-tab, then click Backup settings.

In the pop-up Backup settings window, click the switch button under Local remaining available space protection to turn this feature on or off.

Related APIs

API	Description
DescribeBackupPolicy	Call DescribeBackupPolicy API to query the backup policy.
ModifyBackupPolicy	Call ModifyBackupPolicy API to modify the backup policy.

Last updated: 2025.11.17 20:31:11