Cisco HyperFlex 4.0 introduces support for the HyperFlex CSI plugin based on the Kubernetes Container Storage Interface (CSI) specification. The HX-CSI plugin is leveraged to provision and manage persistent volumes in Kubernetes v1.13 and later. The Cisco HyperFlex CSI plugin driver is deployed as containers.
Before CSI volume plugins were “in-tree” meaning their code was part of the core Kubernetes code and shipped with the core Kubernetes binaries. Storage vendors wanting to add support for their storage system to Kubernetes (or even fix a bug in an existing volume plugin) were forced to align with the Kubernetes release process. In addition, third-party storage code caused reliability and security issues in core Kubernetes binaries and the code was often difficult (and in some cases impossible) for Kubernetes maintainers to test and maintain. CSI is "out-of-tree" meaning that with CSI, third-party storage providers can write and deploy plugins exposing new storage systems in Kubernetes without ever having to touch the core Kubernetes code. This gives Kubernetes users more options for storage and makes the system more secure and reliable.
The HX FlexVolume Driver, supported with HX 3.0 and HX 3.5, is hereby deprecated. The HX FlexVolume Driver was an external volume driver for Kubernetes. It ran in a K8S Node VM and provisioned a requested persistent volume that was compatible with the Kubernetes iSCSI volume.
Cisco, HyperFlex [HCI]/4.0, x86
Container Orch. Interconnect, Containers, Workload Support