Error: OS Errno 28 – No Space Left on Device

Issue

One or more connectors are failing with the following error:

OS Errno 28 - No space left on device.

The error is displayed in the Fivetran dashboard, even though there is plenty of disk space.

Environment

MySQL destination

Resolution

This is a complex issue and there are multiple potential resolutions. To resolve the issue, you can do one of the following:

• Increase the instance size that the database is running on (particularly the RAM).
• Increase the InnoDB buffer pool size.
• Delete old or unused data to clear disk space.
• Add a significant amount of disk space as an extra overflow.

However, we recommend that you migrate to a more robust and scalable data warehouse platform such as Snowflake, BigQuery, or Redshift.

Cause

This can occur when Fivetran runs any SQL query (such as a JOIN operation) on the destination. If the RAM available to the instance that runs the database or the InnoDB buffer pool size is not sufficient for the query at that time, a temporary table is created on the disk. This table can be large in some cases, even though only small amounts of data are being transferred.

Because of this limitation with MySQL database as a destination, Fivetran throws the following warning when you try to set this as a destination:

WARNING: MySQL database can fail to perform basic queries for even medium volumes of data and is not appropriate as a destination. We support MySQL database as a test environment. If you run into these limitations, you will need to migrate to a supported destination.