Amazon Web Services says some customer data stored in its Bahrain and United Arab Emirates cloud infrastructure cannot be recovered, six months after Iranian strikes damaged data centers in both countries.

The physical damage exceeded AWS’s multi-zone resilience design in Bahrain. In a September 15 update to the AWS Health Dashboard, the company said damage there spanned multiple Availability Zones and “exceeded what our regional and multi-AZ services are designed to withstand.” AWS concluded that it cannot restore access to resources and data hosted exclusively in the Middle East (Bahrain) region.

AWS reached a similar conclusion for one of the three Availability Zones in its Middle East (UAE) region. Resources and data hosted exclusively in mec1-az2 are no longer recoverable, although AWS is continuing work on regional resources and on resources in the other affected zones, mec1-az1 and mec1-az3. The company has not publicly quantified how much customer data was lost or how many customers suffered permanent losses.

The incident demonstrates a limit of availability-zone redundancy when physical destruction affects several zones at once. AWS designs Availability Zones as isolated infrastructure locations within a region so customers can distribute applications across them. But regional resilience does not by itself provide protection against an event that disables multiple zones simultaneously. Customers requiring protection against that class of failure need recoverable copies or workloads outside the affected region.

That distinction became important immediately after the attacks. AWS had advised affected customers to migrate workloads to other regions and restore inaccessible resources from remote backups. Most customers subsequently re-established operations elsewhere by restoring backups or copying data that remained accessible, according to AWS.

The outages began with Iranian drone strikes in early March. AWS facilities in Bahrain and the UAE were damaged during the conflict that followed U.S.-Israeli attacks on Iran. By April 30, AWS was warning that restoration would take several months and had suspended billing in the affected regions.

The permanent losses turn what had been an extended regional cloud outage into a broader Internet-infrastructure resilience case: geographically separated facilities within a cloud region can still share exposure to war and other large-scale physical events. AWS continues recovery work in the UAE and says replacement of affected infrastructure will take additional months.