HP StorageWorks 2300 Modular Smart Array reference guide (500911-001, January 2009)

HP StorageWorks 2300 Modular Smart Array reference guide 107
Glossary
chunk size The amount of contiguous data that is written to a vdisk member before moving to the next
member of the vdisk.
dedicated spare A disk that is reserved for use by a specific vdisk to replace a failed disk.
default mapping Host-access settings that are configured when a volume is created.
dual-port disk A dual-port disk is connected to both controllers so its data path is fault tolerant.
dynamic spare A properly sized available disk that is automatically assigned, if the dynamic spares option
is enabled, to replace a failed disk in a redundant vdisk.
EC Expander Controller. The processor (located in the SAS expander in each controller module
and expansion module) that is primarily responsible for enclosure management and SES.
EMP Enclosure management processor. An EC subsystem that provides SES data such as
temperature, power supply and fan status, and the presence or absence of disks.
FC Fibre Channel interface protocol.
global spare A disk that is reserved for use by any redundant vdisk to replace a failed disk.
host An external port that the storage system is attached to. The external port may be a port in
an I/O adapter in a server, or a port in a network switch.
leftover The state of a disk when its metadata says the disk is a member of a vdisk but other
members' metadata say the disk isn't a member. The metadata must be cleared before the
disk can be used in a new vdisk or as a spare.
loop Fibre Channel Arbitrated Loop (FC-AL) topology.
masking Volume-mapping settings that specify no access to that volume by hosts.
master volume A volume that is enabled for snapshots and has an associated snap pool.
MC Management Controller. The processor (located in a controller module) that is primarily
responsible for human-computer interface and computer-computer interface functions, and
interacts with the SC.
metadata Data in the first sectors of a disk drive that stores all disk, vdisk, and volume specific
information including vdisk membership or spare identification, vdisk ownership, volumes
and snapshots in the vdisk, host mapping of volumes, and results of the last media scrub.
point-to-point Fibre Channel Point-to-Point topology.
SAS Serial Attached SCSI interface protocol or disk-drive architecture.
SATA Serial ATA disk-disk architecture.
SC Storage Controller. The processor (located in a controller module) that is primarily
responsible for RAID controller functions. The SC is also referred to as the RAID controller.
SES SCSI Enclosure Services.
single-port disk A single-port disk is connected to both controllers so its data path is not fault tolerant. A
single-port disk's type is shown as SAS-S or SATA-S.
snap pool A volume that stores data that is specific to snapshots of an associated master volume,
including copy-on-write data and data written explicitly to the snapshots. A snap pool
cannot be mapped.
snapshot A “virtual” volume that preserves the state of a master volume’s data as it existed when the
snapshot was created. Data associated with a snapshot is recorded in both the master
volume and in its associated snap pool. A snapshot can be mapped and written to.
SSD Solid-state drive.
vdisk A "virtual" disk comprising the capacity of one or more disks. The number of disks that a
vdisk can contain is determined by its RAID level.
volume A portion of the capacity of a vdisk that can be presented as a storage device to a host.