Run-flat mode

Portworx CSI requires a key-value database such as etcd for configuring storage. A highly available clustered etcd with persistent storage is preferred. You can let Portworx CSI spin up its own key-value database by using the internal KVDB.

An always available key-value database is essential to keep Portworx CSI running smoothly. However, if the internal KVDB nodes go offline, Portworx CSI goes into run-flat mode.

In run-flat mode, all existing volumes currently attached and in use by applications will remain online without any disruption to I/O operations. However, new volume creation, attachment, detachment, and deletion requests will not be processed.