Connecting Hosts
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DataDirect Networks EF4024 FC RAID System Setup Guide | 22
This chapter provides information on how to connect your hosts to the EF4024 FC RAID
system.
3.1
Host System Requirements
Hosts connected to an EF4024 controller enclosure must meet the following requirements:
• Depending on your system configuration, host operating systems may require that
multipathing is supported.
• If fault tolerance is required, then multipathing software may be required. Host-based
multipath software should be used in any configuration where two logical paths
between the host and any storage volume may exist at the same time. This would
include most configurations where there are multiple connections to the host or
multiple connections between a switch and the storage.
Use native Microsoft MPIO DSM support with Windows Server 2008 and Windows
Server 2013. Use either the Server Manager or the command-line interface (
mpclaim
CLI tool) to perform the installation.
See the following web sites for information on using native Microsoft MPIO DSM:
http://support.microsoft.com/gp/assistsupport
http://technet.microsoft.com
(search for “multipath I/O overview”)
3.1.1
Cabling Considerations
Common cabling configurations address hosts, controller enclosures, drive enclosures, and
switches. Host interface ports on EF4024 controller enclosures can connect to respective
hosts via direct-attach or switch-attach.
Qualified options support cable lengths of 1 m (3.28'), 2 m (6.56'), 5 m (16.40'), 15 m (49.21'),
30 m (98.43'), and 50 m (164.04') for OM4 multimode optical cables and OM3 multimode FC
cables, respectively. A 0.5 m (1.64') cable length is also supported for OM3.
3.2
Connecting Enclosures to Hosts
A
host
identifies an external port to which the storage system is attached. Cable connections
vary depending on configuration. This section shows a few common cabling configurations.
NOTE :
EF4024 controllers use Unified LUN Presentation (ULP)—a controller feature
enabling a host to access mapped volumes through any controller host
port.
ULP can show all LUNs through all host ports on both controllers, and the interconnect
information is managed by the controller firmware. ULP appears to the host as an
active-active storage system, allowing the host to select any available path to access the
LUN, regardless of vdisk ownership.
