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SN0054614-00 K Glossary-5
SANsurfer FC/CNA HBA CLI User’s Guide
Command Line Interface for QLogic FC and FCoE Adapters
input/output control
See IOCTL.
intelligent interleaved direct memory
access
See iiDMA.
inter-switch link
See ISL.
IOCTL
Input/output control. A system call in
UNIX/Linux systems. Allows an application
to control or communicate with a device
driver outside usual read/write operations.
IOPS
Input/output operations per second is a
common performance-based measure-
ment calculated by benchmarking applica-
tions, and is primarily used with servers to
find the best storage configuration.
ISL
Inter-switch link. The connection between
two switches using E_Ports.
JBOD
“Just a bunch of disks.” As opposed to a
SAN.
See SAN.
just a bunch of disks
See JBOD.
L_Port
Loop port. Does arbitrated loop functions
and protocols. NL_Ports and FL_Ports are
examples of loop-capable ports. See also
E_Port, F_Port, FL_Port, G_Port, N_Port,
NL_Port.
LIP
Loop initialization process. The initializa-
tion 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 transmis-
sion on the loop is suspended during a LIP.
load balancing
A software feature that improves system
performance by balancing device access
between multiple adapters for maximum
resource efficiency. Available in Windows
2000/Windows Server 2003, Novell
NetWare, and Red Hat/SUSE Linux.
logical unit number
See LUN.
loop ID
The device’s AL_PA on the loop.
loop initialization process
See LIP.
loop port
See L_Port.
loopback
Diagnostic tool that routes transmit data
through a loopback connector back to the
same adapter.
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.