What is GitLab CI Runner System Disk Full

Resolving 'Runner System Disk Full' in GitLab CI

Understanding GitLab CI

GitLab CI is a powerful tool integrated within GitLab that allows developers to automate the testing and deployment of their code. It uses runners to execute jobs defined in the .gitlab-ci.yml file, providing a seamless CI/CD experience.

Identifying the Symptom

One common issue that developers encounter is the 'Runner System Disk Full' error. This problem manifests when the runner's system disk reaches its capacity, causing job executions to fail. You might see error messages indicating insufficient disk space or jobs being unable to start.

Common Error Messages

ERROR: Job failed (system failure): No space left on device FATAL: could not write to disk

Exploring the Issue

The root cause of this issue is straightforward: the disk space allocated to the runner is full. This can happen due to large build artifacts, logs, or other temporary files consuming space over time. Without sufficient disk space, the runner cannot execute new jobs.

Impact on CI/CD Pipeline

When the runner's disk is full, it disrupts the CI/CD pipeline, leading to delayed deployments and testing. This can affect the overall productivity of the development team.

Steps to Resolve the Issue

To resolve the 'Runner System Disk Full' issue, follow these steps:

1. Free Up Disk Space

Start by identifying and removing unnecessary files. You can use the following commands to locate large files and directories:

du -sh * | sort -h

Remove files that are no longer needed:

rm -rf /path/to/unnecessary/files

2. Increase Disk Size

If freeing up space is not sufficient, consider increasing the disk size. This can be done by resizing the disk in your cloud provider's console or by adding additional storage.

3. Configure Log Rotation

Implement log rotation to prevent logs from consuming excessive disk space. Configure logrotate to manage log files efficiently:

/etc/logrotate.conf

For more information, refer to the logrotate manual.

Preventive Measures

To avoid encountering this issue in the future, consider the following preventive measures:

Regularly monitor disk usage and set up alerts for high disk usage. Automate cleanup of old build artifacts and logs. Ensure adequate disk space is allocated when setting up new runners.

For more detailed guidance on managing GitLab runners, visit the official GitLab Runner documentation.