Overview

Datastore Types

Storage in OpenNebula is designed around the concept of Datastores. A Datastore is any storage medium to store disk images. OpenNebula distinguishes between three different Datastore types:

• Images Datastore, which stores the base operating system images, persistent data volumes, CD-ROMs.

• System Datastore holds disks of running Virtual Machines. Disk are moved from/to the Images when the VMs are deployed/terminated.

• Files & Kernels Datastore to store plain files (not disk images), e.g. kernels, ramdisks, or contextualization files. See details here.

Image Datastores

There are different Image Datastores depending on how the images are stored on the underlying storage technology:

• NFS/NAS

• Local Storage

• OneStor

• Ceph

• SAN

• Raw Device Mapping

• iSCSI - Libvirt, to access iSCSI devices through the built-in QEMU support

System Datastores

Each datastore supports different features, here is a basic overview:

	NFS/NAS	SSH	OneStor	Ceph	SAN	iSCSI
Disk snapshots	yes	yes	yes	yes	no	no
VM snapshots	yes	yes	yes	no	no	no
Live migration	yes	yes	yes	yes	yes	yes
Fault tolerance (VM ha)	yes	no	no	yes	yes	yes

How Should I Read This Chapter

Before reading this chapter make sure you are familiar with Node Deployment from Open Cloud Deployment.

After that, proceed with the specific Datastore documentation you might be interested in.

Hypervisor Compatibility

This chapter applies to KVM and LXC.

Warning

Hypervisor limitations:

• LXC Node only supports NFS/NAS, Local Storage and Ceph datastores

For a storage guide on the legacy vCenter driver, see vCenter Storage.