Volume-backed is a type of Virtual Machine where the boot disk data is stored on distributed network storage using HDD drives. Cinder volumes are used as boot disks.
Important: When creating a Volume-backed Virtual Machine, a volume is automatically created.
For Local instance type Virtual Machines, storage is located on local SSD drives.
Accordingly, the cost of disk storage for Volume-backed Virtual Machines is calculated according to HDD rates, while for Local instance type Virtual Machines, it is calculated according to SSD rates.
Note that Backup, Create Snapshot, Rescue, and Rebuild operations are available only for Virtual Machines of the Local type.
Comparison of performance speed between Volume-backed and Local instance types