ReadWriteMany

ReadWriteMany (RWX) is an access mode for Kubernetes PersistentVolume (PV) and PersistentVolumeClaim (PVC) resources that allows the volume to be mounted as read-write by multiple pods across different nodes simultaneously. This contrasts with ReadWriteOnce (RWO), which allows a volume to be mounted read-write on a single node, and ReadOnlyMany (ROX), which provides read-only access from many nodes.

RWX is supported by storage backends that provide a shared filesystem or networked access, such as NFS, CephFS, GlusterFS, and cloud file services like Amazon EFS, Azure Files, and Google Filestore. It is not universally available on all providers or CSI drivers; block storage offerings like AWS EBS, Google Persistent Disk, and Azure Disk typically implement RWO and do not support RWX.

To use RWX, a Kubernetes manifest must request the RWX access mode in the PVC (accessModes: - ReadWriteMany). The underlying storage must be provisioned to be mountable by multiple nodes, and the CSI driver or storage class must expose RWX capabilities. Some environments require dynamic provisioning via CSI or specific configuration in the storage backend.

Considerations include data consistency, locking semantics, and performance characteristics, which vary by backend. Applications designed for concurrent writes from multiple pods should coordinate access to shared files to avoid conflicts. RWX is commonly used for shared data sets, content repositories, log aggregation, and other scenarios where multiple pods must read and write to the same storage resource. See also: Access modes; PersistentVolume; PersistentVolumeClaim; CSI.