Proware DP-503-F4A3, Installation And User Manual

Page: 19 / 84

DP-503-F4A3 RAID SUBSYSTEM
Installation and User Manual 19
The following elements are the connectivity of storages and Server components using the Fibre
channel technology.
Cables and connectors
There are different types of cables of varies lengths for use in a Fibre Channel configuration.
Two types of cables are supported: Copper and Optical (fiber). Copper cables are used for
short distances and transfer data up to 30 meters per link. Fiber cables come in two distinct
types: Multi-Mode fiber (MMF) for short distances (up to 2km), and Single-Mode Fiber
(SMF) for longer distances (up to 10 kilometers). B y d e f a u l t , t h e R A I D s u b s y s t e m
supports two short-wave multi-mode fibre optic SFP connectors.
Fibre Channel Adapter
Fibre Channel Adapter is a device that is connected to a workstation, server, or host system and
control the protocol for communications.
Hubs
Fibre Channel hubs are used to connect up to 126 nodes into a logical loop. All connected nodes
share the bandwidth of this one logical loop. Each port on a hub contains a Port Bypass
Circuit(PBC) to automatically open and close the loop to support hot pluggability.
Switched Fabric
Switched fabric is the highest performing device available for interconnecting large number of
devices, increasing bandwidth, reducing congestion and providing aggregate throughput.
Each device is connected to a port on the switch, enabling an on-demand connection to every
connected device. Each node on a Switched fabric uses an aggregate throughput data path to
send or receive data.
1.4.4 LUN Masking
LUN masking is a RAID system-centric enforced method of masking multiple LUNs behind a
single port. By using World Wide Port Names (WWPNs) of server HBAs, LUN masking is
configured at the volume level. LUN masking also allows s h a r i n g disk storage resource
across multiple independent servers. A single large RAID device can be sub-divided to serve a
number of different hosts that are attached to the RAID through the SAN fabric with LUN
masking. So that only one or a limited number of servers can see that LUN, each LUN inside the
RAID device can be limited.
LUN masking can be done either at the RAID device (behind the RAID port) or at the server HBA.
It is more secure to mask LUNs at the RAID device, but not all RAID devices have LUN masking
capability. Therefore, in order to mask LUNs, some HBA vendors allow persistent binding at the
driver-level.
1.5 Array Definition
1.5.1 Raid Set