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SANsurfer FC HBA Manager User’s Guide
Management Tool for QLogic FC and FCoE Adapters
Glossary-2 SN0054651-00 F
S
Device
A computer subsystem, such an adapter
card, which mediates data in a computer
network. The term “device” is used inter-
changeably with “target” and “target
device”. See FCoE.
Driver
Software that interfaces between the file
system and a physical data storage device
or network media.
The level structure for Windows drivers is
as follows:
Class driver is the highest driver level.
There is a separate class for disk,
Ethernet, and so on. This level handles
all generic aspects of operations for
that class.
Port driver is the middle driver level,
which handles aspects of the operation
specific to the port type; for example,
there is a port driver for SCSI.
Miniport driver is the lowest driver
level and device specific. This level is
usually supplied by the manufacturer
as a companion to a physical device.
Monolithic driver level combines the
functions of different driver levels in the
same driver to increase performance.
Adjunct driver level works along side
a driver at the same level to increase
performance.
In NetWare, the required drivers include:
Host Adapter Module (HAM) is the
driver component associated with the
host adapter hardware. It provides the
functionality to route requests to the
bus where a specified device is
attached.
Custom Device Module (CDM) is the
driver component associated with
storage devices. It provides the
functionality to build device-specific
commands from I/O messages
received from NetWare's Media
Manager.
In Red Hat/SUSE Linux, the driver layers
include:
SCSI Upper Layer is the device
management layer. It handles
device-dependent tasks for devices,
such as disks and tapes.
SCSI Middle Layer is the SCSI traffic
handling layer. It directs requests
between the kernel and the SCSI.
SCSI Lower Layer is the SCSI
adapter driver. It communicates
directly to the SCSI adapter.
The structure for Solaris SPARC/x86
drivers includes:
Nexus drivers provide bus mapping
and translation services to subordinate
nexus and leaf devices. These include
drivers for PCI-to-PCI bridges,
PCMCIA adapters, and SCSI
adapters.
Leaf drivers provide the traditional
character and block driver interfaces
for reading and writing data to storage
and communication devices. These
include drivers for peripheral devices,
including QLA2xxx adapters, disks,
tapes, network adapters, and frame
buffers.
In Macintosh, the driver layers include:
Upper Layer is the device manage-
ment layer. It handles device-depen-
dent tasks for devices, such as disks
and tapes.
Middle Layer is the SCSI traffic
handling layer. It directs requests
between the kernel and the SCSI.