Cable host servers to the storage system
This section describes the different ways that host servers can be connected to a storage system.
Topics:
•
•
Connecting the enclosure to hosts
•
Cabling considerations
Host interface ports on ME4 Series controller enclosures can connect to respective hosts using direct-attach or switch-attach methods.
Another important cabling consideration is cabling controller enclosures to enable the replication feature. The FC and iSCSI product
models support replication, but SAS product models do not support replication. See
Use only Dell EMC cables for host connections:
•
Qualified 16 Gb FC SFP+ transceivers and cable options
•
Qualified 10 GbE iSCSI SFP+ transceivers and cable options
•
Qualified 10Gbase-T cable options
•
Qualified 12 Gb mini-SAS HD cable options
Connecting the enclosure to hosts
A
host
identifies an external port to which the storage system is attached. The external port may be a port in an I/O adapter (such as an
FC HBA) in a server. Cable connections vary depending on configuration. This section describes host interface protocols supported by
ME4 Series controller enclosures, while showing a few common cabling configurations. ME4 Series controllers use Unified LUN
Presentation (ULP), which enables 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 disk group ownership.
CNC technology
The ME4 Series FC/iSCSI models use Converged Network Controller (CNC) technology.
The CNC technology enables you to select the host interface protocols to use on the storage system. The small form-factor pluggable
(SFP+) connectors that are used in CNC ports are further described in the following subsections:
NOTE:
• Controller modules are not always shipped with preinstalled SFP+ transceivers. You might need to install SFP
transceivers into the controller modules. Within your product kit, locate the qualified SFP+ transceivers and install
them into the CNC ports. See
SFP+ transceiver for FC/iSCSI ports
.
• Use the ME Storage Manager to set the host interface protocol for CNC ports using qualified SFP+ transceivers.
ME4 Series models ship with CNC ports configured for FC. When connecting CNC ports to iSCSI hosts, you must
configure these ports for iSCSI.
CNC ports used for host connection
ME4 Series SFP+ based controllers ship with CNC ports that are configured for FC.
If you must change the CNC port mode, you can do so using the ME Storage Manager.
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Cable host servers to the storage system