liveBook · Manning

Readwritemany

As explained in Kubernetes in Action, Second Edition

ReadWriteMany is a Kubernetes volume access mode that permits a volume to be attached read-write concurrently to multiple nodes.

ReadWriteMany (RWX) is a Kubernetes volume access mode that lets multiple nodes attach the same volume concurrently while allowing read and write operations. It supports workloads whose pods run on different nodes and share files. section 10.2.4

Keep these operational distinctions in mind:

  • RWX removes the single-node restriction that causes multi-attach failures with read-write-once storage. section 10.2.4
  • Support depends on the storage technology; a cluster’s default StorageClasses may not provide ReadWriteMany. section 10.2.4
  • Test the mode by selecting an RWX-capable storageClassName in a PersistentVolumeClaim and creating pods that may schedule on different nodes. section 10.2.4
$ gcloud container clusters update <cluster-name> \
   --update-addons=GcpFilestoreCsiDriver=ENABLED

On Google Kubernetes Engine, enable the GcpFilestoreCsiDriver to make additional ReadWriteMany-capable StorageClasses available; the Cloud Filestore API is also required. section 10.2.4

How Kubernetes in Action, Second Edition covers it

How deep it goes
Defines concurrent attachment, demonstrates cross-node use procedurally, and notes StorageClass support without detailing storage internals.
Examples
Uses a multi-pod cross-node test and GKE’s GcpFilestoreCsiDriver enablement command.
What it assumes
Assumes Kubernetes PersistentVolumeClaim and pod usage, then introduces storage-class capability as the key platform constraint.
What you can do after
Operate/configure shared storage by choosing an RWX-capable StorageClass and testing pods across nodes.
How it connects
Connects ReadWriteMany to PersistentVolumes, PersistentVolumeClaims, StorageClasses, Kubernetes nodes, pods, and CSI drivers.
Cover of Kubernetes in Action, Second Edition
liveBookmanning.com
Read Kubernetes in Action, Second Edition on liveBook Get the book at manning.com

Related concepts

This explainer was generated by Manning's knowledge graph from the text of Kubernetes in Action, Second Edition. The section links point to the parts of the book it draws on.