Recovery of CL4 S3 Storage Service

9-12. 10. 2026 - Recovery of CL4 S3 Storage Service

Following the recent outage of the CL4 object storage caused by a software bug, we would like to provide an update on the gradual restoration of the service.
The outage and subsequent recovery steps affect only a small fraction of MetaCentrum users (project directories are not affected). All affected users have already received detailed information and instructions via a direct email from DataCare departement. If you have not received this email, your data is not affected.

Current status in brief:

• Writing new data: The software bug has been fixed. The standard endpoint https://s3.cl4.du.cesnet.cz now points to a new S3 instance and is fully available for writes using your existing credentials.
• Existing data: A separate temporary endpoint for existing data will be provided early next week. Storage administrators will progressively verify the data and migrate it to the new endpoint.

For a detailed technical description of the issue and further outage details, please refer to the CESNET Data Storage Department news. If you have any questions, please do not hesitate to contact CESNET DateCare User Support.