Connecting Hosts
96-30065-001 Rev. A0
DataDirect Networks EF4024 FC RAID System Setup Guide | 23
TIP:
See “Configuring the system > Using the Configuration Wizard” in the
EF4024
RAIDar User Guide
to initially configure the system or change system
configuration settings.
The EF4024 controller enclosure supports two controller modules using the Fibre Channel
interface protocol for host connection. Each controller module provides two host ports
designed for use with an FC SFP supporting data rates up to 16 Gbit/s.
TIP:
See Appendix
E, SFP Option for CNC Ports
for information on locating and
installing the SFP transceivers on CNC ports.
The controller supports Fibre Channel Arbitrated Loop (public or private) or point-to-point
topologies. Loop protocol can be used in a physical loop or in a direct connection between
two devices. Point-to-point protocol is used to connect to a fabric switch. See the
set
host-parameters
command described in the
EF4024 CLUI Command Reference
for
command syntax and details about parameter settings relative to supported link speeds.
For attachment to FC hosts directly, or through a switch used for the FC traffic, the host
computer needs to support FC and optionally, multipath I/O.
TIP:
Use the RAIDar Configuration Wizard to set FC port speed. In the
EF4024 RAIDar
User Guide
, see “Configuring the system > Using the Configuration Wizard >
Configuring host ports,” and go to FC port options. Use the
show
host-parameters
or
show ports
CLUI commands to view information
about host ports.
3.2.1
Dual-Controller Configurations
The EF4024 dual-controller configuration improves application availability because in the
event of a controller failure, the affected controller fails over to the partner controller with
little interruption to data flow. A failed controller can be replaced without the need to shut
down the storage system.
In a dual-controller system, hosts use LUN-identifying information from both controllers to
determine that up to four paths are available to a given storage volume. Assuming MPIO
software is installed, a host can use any available data path to access a volume owned by
either controller. The path providing the best performance is through host ports on the
volume’s owning controller. Both controllers share one set of 1,024 LUNs (0-1,023) for use in
mapping volumes to hosts (see “ULP” in the
EF4024 RAIDar User Guide
).
3.2.2
Direct Attach Configurations
The EF4024 controller enclosures support up to four direct-connect server connections, two
per controller module.
Figure 13
and
Figure 14
below show examples for connecting one and two servers to the
EF4024 controller enclosures.
