Overview
LEDs
Note An n+1 redundant system has either two or three power supplies, which may be in any slot.
Grid Redundancy
The grid redundant configuration is sometimes used when you have two power sources to power a chassis or you require greater than N+1 redundancy. If one source fails (which causes a loss of power to one or two power supplies), the surviving power supplies on the other power circuit continue to provide power to the chassis. A common reason for using grid redundancy is if the rack power distribution is such that power is provided by two PDUs and you want the grid redundancy protection in the case of a PDU failure.
To provide grid redundant (or greater than N+1) protection, the following number of power supplies is recommended:
•Four power supplies are recommended if the power configuration for that chassis requires greater than 2500W or if using Cisco UCS Release 1.4(1) and later releases
•Two power supplies are recommended if the power configuration for that chassis requires less than 2500W or the system is using Cisco UCS Release 1.3(1) or earlier releases
Note Both grids in a power redundant system should have the same number of power supplies. If your system is configured for grid redundancy, slots 1 and 2 are assigned to grid 1 and slots 3 and 4 are assigned to grid 2. If there are only two power supplies (PS) in the a redundant mode chassis, they should be in slots 1 and 3. Slot and cord connection numbering is shown below.
Figure 11: Power Supply Bay and Connector Numbering
Front
Server Slot 1
Server Slot 3
Server Slot 5
Server Slot 7
PS 1 |
| PS 2 |
|
|
|
Server Slot 2
Server Slot 4
Server Slot 6
Server Slot 8
PS 3 |
| PS 4 |
|
|
|
I/O Module Slot 1
Rear
Fan 1
Fan 5
Connector PS 4
Fan 2 |
| Fan 3 | |
Fan 6 | Module Slot 2 | Fan 7 | |
I/O | |||
|
| ||
Connector |
| Connector | |
PS 3 |
| PS 2 |
LEDs
Fan 4
Fan 8
Connector PS 1
279770
LEDs on both the chassis and the modules installed within the chassis identify operational states, both separately and in combination with other LEDs.
Cisco UCS 5108 Server Chassis Installation Guide
23 |