If your PostgreSQL service runs out of disk space, the service will start malfunctioning. This will also prevent creating proper backups. 

To prevent this situation, Aiven automatically detects when your service is running out of free space and prevents further write operations to it by setting the default_transaction_read_only  parameter to  ON.

At this point, clients will start seeing errors like cannot execute CREATE TABLE in a read-only transaction.

How to increase the available space

Upgrade to a larger plan

You can do this either from the Aiven web console or with the Aiven CLI client. New nodes with more disk space are launched once the upgrade is confirmed.

To do this in the Aiven web console:

  1. Go to the Overview page of your Aiven for PostgreSQL service.

  2. Scroll down to Service plan and click Upgrade Plan.

  3. Select your new plan and click Upgrade.

Once the data is on the new nodes with more disk space, the disk usage returns to below the critical level and the system automatically sets the default_transaction_read_only parameter to OFF to allow write operations again.

Delete data

You can also delete data from your database, but since your service is set to read-only mode, this also prevents the deletion of data.

There are two ways to work around this:

  1. Run the following command to change the transaction mode to read-write for your session:

    SET default_transaction_read_only = OFF;

    You can then delete data within your session.

  2. Send the following POST request using our API:


    This enables write operations for the next 15 minutes, allowing you to free up space.

If you upgrade your service temporarily to delete data, you may have to wait for the next backup to complete before you can downgrade to a smaller plan.

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