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SANsurfer FC HBA CLI User’s Guide
Command Line Interface for QLogic Fibre Channel Host Bus Adapters
Glossary-4 SN0054614-00 F
S
IOCB
I/O control block. An IOCB is a command
structure in QLogic ISP architecture.
ioctl (input/output control)
A system call in Unix/Linux systems.
Allows an application to control or commu-
nicate with a device driver outside usual
read/write operations.
JBOD (Just a Bunch of Disks)
As opposed to a SAN.
See SAN (Storage
Area Network).
L_Port (Loop Port)
Does arbitrated loop functions and proto-
cols. NL_Ports and FL_Ports are
examples of loop-capable ports. See
E_Port (Expansion Port), F_Port, FL_Port
(Fabric Loop Port), G_Port (Generic Port),
N_Port (Node Port), NL_Port (Node Loop
Port).
LIP (Loop Initialization Process)
The initialization process in an arbitrated
loop that occurs when the loop is powered
up or a new device is added. One function
of a LIP is to assign addresses. All data
transmission on the loop is suspended
during a LIP.
load balancing
A software feature that improves system
performance by balancing device access
between multiple HBAs for maximum
resource efficiency. Available in Windows
2000/Windows Server 2003, Novell
NetWare, and Red Hat/SuSE Linux.
loopback
Diagnostic tool that routes transmit data
through a loopback connector back to the
same HBA.
loop ID
The device’s AL_PA on the loop.
LUN
Logical Unit Number, a subdivision of a
SCSI target. It is the small integer handle
that differentiates an individual disk drive
or partition (volume) within a common
SCSI target device such as a disk array.
Technically, a LUN can be a single
physical disk drive, multiple physical disk
drives, or a portion (volume) of a single
physical disk drive. However, LUNs are
typically not entire disk drives but rather
virtual partitions (volumes) of a RAID set.
Using LUNs, the FC host can address
multiple peripheral devices that may share
a common controller.
LUN masking
A software feature that assigns LUNs to
specific servers or hides LUNs from
specific servers for maximum access and
availability control.
media
Physical-layer information carriers. FC
supports several different physical media:
copper, multimode optical, and
single-mode optical. All FC protocols are
supported on all media.
NPIV
N_Port ID Virtualization.
N_Port (Node Port)
A port that connects by a point-to-point link
to either a single N_Port or a single
F_Port. N_Ports handle creation, detec-
tion, and flow of message units to and from
the connected systems. N_Ports are end
ports in virtual point-to-point links through
a fabric, for example N_Port to F_Port to
F_Port to N_Port using a single FC fabric
switch. See F_Port (Fabric Port).