ReadWriteOnce is a Kubernetes volume access mode that lets one node attach a volume for read-write use. Multiple pods may use it when they run on that same node. section 10.2.4
The scheduling and attachment behavior is the important distinction:
- Pods scheduled on the volume's node can run and read or write shared files. section 10.2.4
- Pods scheduled on another node can remain in ContainerCreating because the volume cannot attach to multiple nodes. section 10.2.4
- Unlike ReadWriteOncePod, ReadWriteOnce permits several pods on one node to use the volume simultaneously. section 10.2.4
Several pods sharing one volume
A BusyBox pod mounts a ReadWriteOnce PersistentVolumeClaim at /mnt/volume, lists existing files, and writes a file named after its hostname. Pods on the same node run successfully and see one another's files; pods on another node wait for attachment.
