HP Integrity NonStop i NS2300, Planning Manual

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Enterprise Storage System — ESS (Optional)
An Enterprise Storage System (ESS) is a collection of magnetic disks, their controllers, and a
disk cache in one or more standalone racks. ESS connects to the NS2300 system either directly
via Fibre Channel ports on the Storage CLIM (direct connect) or through a separate storage area
network (SAN) using a Fibre Channel SAN switch (switched connect). For more information
about these connection types, see your Hewlett Packard Enterprise service provider.
NOTE: The Fibre Channel SAN switch power cords might not be compatible with the modular
rack PDU. Contact your Hewlett Packard Enterprise service provider to order replacement power
cords for the SAN switch that are compatible with the modular rack PDU.
Cables and switches vary, depending on whether the connection is direct, switched, or a
combination:
Fibre Channel Switches Cables Connection
0 2 Fibre Channel (FC) HBA interfaces
on Storage CLIM (LC-MMF)
1
Direct connect
1 or more 4 FC HBA interfaces on Storage
CLIM (LC-MMF) Switched
1 2 FC HBA interfaces on Storage
CLIM for each direct connection Combination of direct and switched
1 4 FC HBA interfaces on Storage
CLIM for each switched connection
1
Customer must order FC HBA interfaces for a pair of Storage CLIMs.
For fault tolerance, the primary and backup paths to an ESS logical device (LDEV) must go
through different Fibre Channel switches.
Some storage area procedures, such as reconfiguration, can cause the affected switches to
pause. If the pause is long enough, I/O failure occurs on all paths connected to that switch. If
both the primary and the backup paths are connected to the same switch, the LDEV goes down.
For more information, see the documentation that accompanies the ESS.
NS2300 Standard and Optional Hardware 19