Storage on Controller Hosts

The controllers provide storage for the OpenStack Controller Services through a combination of local container ephemeral disk, Persistent Volume Claims backed by Ceph and a containerized HA mariadb deployment.

On systems configured for controller storage with a small Ceph cluster on the master/controller nodes, they also provide persistent block storage for persistent VM volumes (Cinder), storage for VM images (Glance), and storage for VM remote ephemeral volumes (Nova). On All-in-One Simplex or Duplex systems, the controllers also provide nova- local storage for ephemeral VM volumes.

On systems configured for controller storage, the master/controller’s root disk is reserved for system use, and additional disks are required to support the small Ceph cluster. On a All-in-One Simplex or Duplex system, you have the option to partition the root disk for the nova-local storage (to realize a two-disk controller) or use a third disk for nova-local storage.

Underlying Platform Filesystem Storage

See the Planning Overview documentation for details.

To pass the disk-space checks, any replacement disks must be installed before the allotments are changed.

Glance, Cinder, and Remote Nova storage

On systems configured for controller storage with a small Ceph cluster on the master/controller nodes, this small Ceph cluster on the controller provides Glance image storage, Cinder block storage, Cinder backup storage, and Nova remote ephemeral block storage. For more information, see Block Storage for Virtual Machines.

Nova-local Storage

Controllers on StarlingX OpenStack Simplex or Duplex systems incorporate the Compute function, and therefore provide nova- local storage for ephemeral disks. On other systems, nova- local storage is provided by compute hosts. For more information about this type of storage, see Storage on Compute Hosts and Block Storage for Virtual Machines.