Each data center must have at least one data storage domain. An ISO storage domain per data center is also recommended. Export storage domains are deprecated, but can still be created if necessary.

A storage domain can be made of either block devices (iSCSI or Fibre Channel) or a file system.

By default, GlusterFS domains and local storage domains support 4K block size. 4K block size can provide better performance, especially when using large files, and it is also necessary when you use tools that require 4K compatibility, such as VDO.

{virt-product-fullname} currently does not support block storage with a block size of 4K. You must configure block storage in legacy (512b block) mode.

The storage types described in the following sections are supported for use as data storage domains. ISO and export storage domains only support file-based storage types. The ISO domain supports local storage when used in a local storage data center.

See:

  • Storage in the Administration Guide.

NFS

NFS versions 3 and 4 are supported by {virt-product-fullname} 4. Production workloads require an enterprise-grade NFS server, unless NFS is only being used as an ISO storage domain. When enterprise NFS is deployed over 10GbE, segregated with VLANs, and individual services are configured to use specific ports, it is both fast and secure.

As NFS exports are grown to accommodate more storage needs, {virt-product-fullname} recognizes the larger data store immediately. No additional configuration is necessary on the hosts or from within {virt-product-fullname}. This provides NFS a slight edge over block storage from a scale and operational perspective.

See:

iSCSI

Production workloads require an enterprise-grade iSCSI server. When enterprise iSCSI is deployed over 10GbE, segregated with VLANs, and utilizes CHAP authentication, it is both fast and secure. iSCSI can also use multipathing to improve high availability.

{virt-product-fullname} supports 1500 logical volumes per block-based storage domain. No more than 300 LUNs are permitted.

See:

Fibre Channel

Fibre Channel is both fast and secure, and should be taken advantage of if it is already in use in the target data center. It also has the advantage of low CPU overhead as compared to iSCSI and NFS. Fibre Channel can also use multipathing to improve high availability.

{virt-product-fullname} supports 1500 logical volumes per block-based storage domain. No more than 300 LUNs are permitted.

See:

Fibre Channel over Ethernet

To use Fibre Channel over Ethernet (FCoE) in {virt-product-fullname}, you must enable the fcoe key on the {engine-name}, and install the vdsm-hook-fcoe package on the hosts.

{virt-product-fullname} supports 1500 logical volumes per block-based storage domain. No more than 300 LUNs are permitted.

See:

oVirt Hyperconverged Infrastructure

oVirt Hyperconverged Infrastructure combines {virt-product-fullname} and {gluster-storage-fullname} on the same infrastructure, instead of connecting {virt-product-fullname} to a remote {gluster-storage-fullname} server. This compact option reduces operational expenses and overhead.

See:

  • Deploying oVirt Hyperconverged Infrastructure for Virtualization

  • Deploying oVirt Hyperconverged Infrastructure for Virtualization On A Single Node

  • Automating Virtualization Deployment

POSIX-Compliant FS

Other POSIX-compliant file systems can be used as storage domains in {virt-product-fullname}, as long as they are clustered file systems, such as Red Hat Global File System 2 (GFS2), and support sparse files and direct I/O. The Common Internet File System (CIFS), for example, does not support direct I/O, making it incompatible with {virt-product-fullname}.

See:

Local Storage

Local storage is set up on an individual host, using the host’s own resources. When you set up a host to use local storage, it is automatically added to a new data center and cluster that no other hosts can be added to. Virtual machines created in a single-host cluster cannot be migrated, fenced, or scheduled.

For {hypervisor-fullname}s, local storage should always be defined on a file system that is separate from / (root). Use a separate logical volume or disk.

See: Preparing and Adding Local Storage in the Administration Guide.