2.2. Block Storage

The Block Storage service now supports incremental backups. With this feature, you can save changes to a volume since its last backup, as opposed to performing a full backup each time. This allows your backup operations to scale better over time as the number and sizes of your volumes grow over time.

To make incremental backups possible, the Block Storage feature now also supports snapshot-based backups. Snapshot-based backups allow you to back up volumes while they are still attached to an instance.

Cinder backup now has support for using both NFS-supplied and POSIX-supplied data repositories as backup targets.

When creating a volume type, you can now set it to private. Private volume types are only accessible in projects where they are explicitly added. If a private volume type has no attached project, only users with the admin role can use them. Private volume types are useful for restricting access to certain volume specifications.

The Block Storage service can now provide the Compute service with all available portal, IQN, and LUN information for accessing a volume. This allows the Compute service to establish multiple sessions for each target, which in turn facilitates failover in case the primary path is down.

The Block Storage service now allows you to set Consistency Groups. With this, you can group multiple volumes together as a single entity; this, in turn, allows you to perform operations on multiple volumes at once, rather than individually. At this time, the only supported operation on consistency groups is snapshot creation.

Note that this capability is only available through the IBM Storwize driver.