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Storage ecosystem

In XCP-ng, VM disks live in a Storage Repository (SR). The XAPI storage module does all the heavy lifting: you point XCP-ng at a disk, a partition, or a network share, and it handles formatting and management for you. SRs can be thin or thick provisioned, and local or shared across a pool.

The canonical reference is the storage section of the XCP-ng documentation, which lists every SR driver and its support status.

Officially supported SR types

  • File based: Local EXT, NFS, File, and XOSTOR (shared, thin provisioned)
  • Block based: Local LVM, iSCSI, and HBA (Fibre Channel and similar)

Additional drivers are provided as-is with less testing: ZFS, XFS, GlusterFS, CephFS, MooseFS, Ceph RBD, and more. File based, thin provisioned SRs (local EXT, NFS, XOSTOR) are the recommended choice: snapshots used by backup jobs cost far less space than on thick provisioned storage.

Any iSCSI or NFS array works out of the box

Because NFS, iSCSI, and HBA are standard protocols, any storage vendor exposing them is compatible with XCP-ng out of the box: point XCP-ng at the share or LUN and it becomes a Storage Repository, with no vendor-specific driver, plugin, or certification needed. If your NAS or SAN speaks NFS or iSCSI, it works, whether or not its vendor appears anywhere in our documentation.

Active storage partnerships

On top of that baseline compatibility, we maintain active partnerships with storage vendors through the Vates Alliance Network: both engineering teams work together on joint validation, documented reference configurations, and deeper integration over time.

  • LINBIT: the partnership behind XOSTOR: LINBIT's open source DRBD and LINSTOR technologies power the hyperconverged storage of XCP-ng.
  • DataCore: StarWind VSAN is certified with XCP-ng, and SANsymphony is compatible over iSCSI and FC (announcement).
  • Nexsan: the Unity series is validated over iSCSI, NFS and FC (announcement).
  • Pure Storage: Vates joined the Everpure Technology Alliance Program, with integration work on the roadmap (announcement).

XOSTOR: hyperconverged storage

XOSTOR is Vates' hyperconverged storage solution, replicating volumes across the hosts of an XCP-ng pool: see the XOSTOR page for the full product description.

Disk formats and the 16 TiB limit

VHD is the historical, still default, disk format, limited to 2 TiB per virtual disk. The QCOW2 format, generally available in XCP-ng 8.3 LTS, raises the limit to 16 TiB; Xen Orchestra automatically selects QCOW2 when you create a larger disk. QCOW2 works on every supported SR type except XOSTOR. See the GA announcement.