FC0054606-00 A
Glossary-5
Fibre Channel Adapter for VMware ESX User’s Guide
A
NL_Port (Node Loop Port)
A port capable of arbitrated loop functions
and protocols. An NL_Port connects
through an arbitrated loop to other
NL_Port and at most a single FL_Port.
NL_Ports handle creation, detection, and
flow of message units to and from the
connected systems. NL_Ports are end
ports in virtual point-to-point links through
a fabric, for example NL_Port to F_Port to
F_Port to N_Port using a single FC fabric
switch. In the absence of a fabric switch
FL_Port, NL_Ports can communicate with
other NL_Ports in virtual point-to-point
links through a FC_AL open loop circuit
often through FC_AL (Arbitrated Loop)
hub or loop switch devices. See:
E_Port
,
F_Port
,
FL_Port
,
G_Port
,
N_Port (Node
Port)
.
NPIV
See
N_Port ID virtualization
.
NVRAM
Non-volatile random access memory. A
type of memory that retains data even
when power is removed. Holds configura-
tion settings. You can configure NVRAM
settings manually or restore them from a
file.
oops
A deviation from correct behavior of the
Linux kernel that produces a certain error
log. The kernel panic condition results
from many kinds of oops, but others may
allow continued operation with compro-
mised reliability. When the kernel detects a
problem, it prints an oops message and
kills any offending process.
path
A path to a device is a combination of a
adapter
port instance
and a target port as
distinct from internal paths in the fabric
network. A fabric network appears to the
operating system as an opaque network
between the adapter (initiator) and the
target.
Because a path is a combination of an
adapter and a target port, it is distinct from
another path if it is accessed through a
different adapter and/or it is accessing a
different target port. Consequently, when
switching from one path to another, the
driver might be selecting a different
adapter (initiator), a different target port, or
both.
This is important to the driver when
selecting the proper method of failover
notification. It can make a difference to the
target device, which might have to take
different actions when receiving retries of
the request from another initiator or on a
different port.
PID (process identifier)
A number used by some operating system
kernels (such as that of UNIX, Mac OS
®
X
or Windows NT) to uniquely identify a
process.
PLOGI (port login)
A port login occurs in a Fibre Channel SAN
when two node ports establish a connec-
tion between each other (typically a device
such as an FC adapter connecting to a
switch).
point-to-point
Also FC-P2P. Two FC nodes directly
connected (not in a loop).