HP StorageWorks 2000 Modular Smart Array Reference Guide (481599-003, August 2008)

306 HP StorageWorks 2000 Family Modular Smart Array reference guide • August 2008
data mirroring Data written to one disk drive is simultaneously written to another disk
drive. If one disk fails, the other disk can be used to run the virtual disk
and reconstruct the failed disk. The primary advantage of disk
mirroring is 100 percent data redundancy: since the disk is mirrored, it
does not matter if one of the disks fails; both disks contain the same
data at all times and either can act as the operational disk. The
disadvantage of disk mirroring is that it is expensive because each disk
in the virtual disk is duplicated. RAID 1 and 10 use mirroring.
data striping The storing of sequential blocks of incoming data on all the different
disk drives in a virtual disk. This method of writing data increases
virtual disk throughput because multiple disks are working
simultaneously, retrieving and storing. RAID 0, 3, 5, 6, 10, and 50 use
striping.
DHCP Dynamic Host Configuration Protocol.
direct attach storage
(DAS) A dedicated storage device that connects directly to one or more
servers. (SNIA)
Supported for the MSA2012fc.
disk mirroring See data mirroring.
drive enclosure An enclosure that contains disk drives and one or two expansion
modules. Drive enclosures can be attached to a controller enclosure to
provide additional storage capacity. See expansion module.
drive module A FRU consisting of a disk drive and drive sled.
dynamic spare An available disk drive that is used to replace a failed drive in a virtual
disk, if the Dynamic Spares feature is enabled and no vdisk spares or
global spares are designated.
EC See Expander Controller (EC).
EMP See enclosure management processor (EMP).
enclosure A physical storage device that contains disk drives. If the enclosure
contains integrated RAID controllers it is known as a controller
enclosure; otherwise it is a drive enclosure.