Prevent running out of disk space#

In the event that your MySQL server runs out of disk space, the service starts malfunctioning. Running out of disk space also prevents backups from being properly created. Check out how Aiven prevents those from happening and how you can make more space available on your disk when needed.

Switch to the read-only mode#

Aiven automatically detects when your service is running out of free space and prevents further writes to it. This process is done by setting the MySQL @@GLOBAL.read_only flag to 1. The threshold for moving to this state is when your disk usage is at 97% or higher.

Once your service is made read-only, the service reports errors when you attempt to insert, update, or delete data:

ERROR 1290 (HY000): The MySQL server is running with the --read-only option so it cannot execute this statement

Free up disk space#

Optimize problem tables#

InnoDB does not reclaim unused disk space by default and this can cause a disk to become full.

Read the help article MySQL disk usage for more information.

Upgrade to a larger plan#

This can be done from within Aiven Console or with the Aiven CLI client. New nodes with more disk capacity are launched, and your existing data is synced to those new nodes. Once the migration is completed, the disk usage drops below the critical level and the read-only state is canceled, allowing writes to be made once more.

Delete data#

As your service is set in read-only mode, attempting to free disk space by deleting data can’t be done directly. To disable the read-only state, you need to use our API to temporarily remove the restriction.

You can use our API and send a POST request to:<PROJECT>/service/<SERVICE_NAME>/enable-writes

The output of a successful operation is:

"message": "Writes temporarily enabled",
"until": "2022-04-22T13:42:05.385432Z"

This way you can free up space within the next 15 minutes.

See also

Consider reading how to reclaim disk space if you are having issues with full disk.