NonStop NS14000 Planning Guide (H06.10+)

Cables and switches vary, depending on whether the connection is direct, switched, or a
combination:
Fibre Channel SwitchesLC-LC CablesConnection
02 Fibre Channel portsDirect connect
1 or more4 Fibre Channel portsSwitched
12 Fibre Channel ports for each direct
connection4 Fibre Channel ports for
each switched connection
Combination of direct and switched
This illustration shows an example of connections between two VIO enclosures and an ESS via
separate Fibre Channel switches:
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.
Refer to the documentation that accompanies the ESS.
Component Location and Identification
Topics discussed in this subsection are:
• “Terminology” (page 66)
• “Rack and Offset Physical Location” (page 67)
• “NonStop Blade Element Group-Module-Slot Numbering” (page 67)
• “LSU Group-Module-Slot Numbering” (page 68)
• “VIO Enclosure Group-Module-Slot Numbering” (page 70)
• “Fibre Channel Disk Module Group-Module-Slot Numbering” (page 72)
Component Location and Identification 65