Administrator Guide

Table 43. Glossary of ME4 Series terms (continued)
Term Definition
HBA Host bus adapter. A device that facilitates I/O processing and physical connectivity between a
host and the storage system.
host A user-defined group of initiators that represents a server.
host group A user-defined group of hosts for ease of management, such as for mapping operations.
host port A port on a controller module that interfaces to a host computer, either directly or
through a network switch.
initiator An external port to which the storage system is connected. The external port may be a port in
an I/O adapter in a server, or a port in a network switch.
I/O Manager An SNMP MIB term for a controller module.
I/O module See IOM
IOM Input/output module, or I/O module. An IOM can be either a controller module or an expansion
module.
IOPS I/O operations per second.
IQN iSCSI Qualified Name.
iSCSI Internet SCSI.
iSNS Internet Storage Name Service.
JBOD “Just a bunch of disks.” See expansion enclosure.
LBA Logical block address. The address used for specifying the location of a block of data.
leftover The state of a disk that the system has excluded from a disk group because the timestamp in
the disk’s metadata is older than the timestamp of other disks in the disk group, or because
the disk was not detected during a rescan. A leftover disk cannot be used in another disk
group until the disk’s metadata is cleared. For information and cautions about doing so, see
documentation topics about clearing disk metadata.
LFF Large form factor.
linear The storage-class designation for logical components such as volumes that do not use
paged-storage technology to virtualize data storage. The linear method stores user data in
sequential, fully allocated physical blocks, using a fixed (static) mapping between the logical
data presented to hosts and the physical storage where it is stored.
linear disk group For linear storage, a group of disks that is configured to use a specific RAID level.
The number of disks that a linear disk group can contain is determined by its RAID level. Any
supported RAID level can be used. When a linear disk group is created, a linear pool with the
same name is also created to represent the volume-containment properties of the disk group.
See also linear pool.
linear pool For linear storage, a container for volumes that is composed of one linear disk group.
LIP Loop Initialization Primitive. An FC primitive used to determine the loop ID for a controller.
lock key A system-generated value that manages the encryption and decryption of data on
FDE-capable disks. See also FDE, passphrase.
loop See FC-AL.
LUN Logical Unit Number. A number that identifies a mapped volume to a host system.
MAC address Media Access Control Address. A unique identifier assigned to network interfaces for
communication on a network.
Management Controller See MC.
map/mapping Settings that specify whether a volume is presented as a storage device to a host system, and
how the host system can access the volume. Mapping settings include an access type (read-
write, read-only, or no access), controller host ports through which initiators may access the
Glossary of terms 185