Asymmetric logical unit access, a feature of some RAID devices that permits automatic path failover

A logical volume element beneath another volume element in the XVM topology tree hierarchy, also known as a piece . A mirror child is known as a leg.

SGI clustered filesystem product

XVM operating mode in which an XVM physical volume (physvol) is owned by a CXFS cluster and it can be controlled by any of the nodes in that cluster. Cluster domain on a server-capable administration node requires that the appropriate CXFS services are started (see “CXFS Service Requirements for Cluster Domain” in Chapter 2). See also local domain.

The enabling/disabling of a node, which changes a flag in the cluster database. This disabling/enabling does not affect the daemons involved. The daemons that control CXFS cluster services are clconfd on a server-capable administration node and cxfs_client on a client-only node.

Concatenated volume element, which combines other volume elements so that their storage is combined into one logical unit.

Default subvolume for storing the contents of the volume.

The mode in which XVM is operating, which affects the ownership and administration of physvols. See cluster domain and local domain.

A disk with an XVM physvol label but which cannot be administered by the current node because it is owned by a different node or a different cluster.

Graphical user interface, either XVM Manager in the local domain or CXFS Manager in the cluster domain

One child of a mirror, on which a volume is replicated.

XVM operating outside of a CXFS cluster or in which an XVM physvol is owned by a single node and it can be controlled only by that node. See also cluster domain.

See volume.

Optional subvolume intended for faster storage for the filesystem journaling which may improve the performance of metadata-intensive operations.

Logical unit, the virtual disk space which can be labeled by XVM to form a physvol. There may be multiple paths to a given LUN.

A RAID device that does not have ALUA and therefore requires the /etc/failover2.conf file to provide path failover

See physvol.

A disk or LUN that has been labeled for use by XVM is a physical volume element, abbreviated to physvol. A physvol with a cluster domain is owned by a CXFS cluster, while a physvol with a local domain is owned by a single node.

A volume element beneath another volume element in the XVM topology tree, also known as a child. A mirror piece is known as a leg.

The number of a child according to its position in the XVM topology tree, beginning with 0,which can be used to specify the object in xvm commands. See also piece, rightmost child, and leftmost child.

Redundant array of independent disks

The first child of a given volume element in the XVM topology tree, having a piece number of 0. See also piece, piece number, and leftmost child.

The last child of a given volume element in the XVM topology tree. For example, if a volume element has three children, the leftmost child would have a piece number of 2. See also piece, piece number, and rightmost child.

An XVM command that does not affect the address space of a subvolume, such as detaching or deleting all but the last child of a mirror. See also unsafe command.

Operations that cross the boundary between one child and the next.

A volume element composed of multiple chunks alternating across the address space to allow parallel I/O operations for higher performance.

A volume element that maintains identical data images on its underlying volume elements, useful when data redundancy and availability are desired

The process of synchronizing data on the legs of a mirror.

A volume element that can be composed of any combination of a stripes, mirrors, concats, and slices.

The hierarchy of volume elements that compose a volume.

A disk that has not been labeled as an XVM disk.

An XVM command that affects the address space of a subvolume, such as detaching or deleting a child of a concat. See also safe command.

See volume element.

A collection of subvolumes, which are grouped together into a single volume name. A volume is topmost XVM volume element,

A building block of an XVM logical volume topology. The following are all volume elements:

The number of volume elements that make up the widest layer in the topology tree of a volume.

The set of paths that are currently used for I/O.

The XVM command line interface, available via the xvm(8) command and subcommands

An unlabeled disk, physvol, foreign disk, or volume element.

The XVM graphical user interface, available via the xvmgr(8) command.