Procedure: Powering off the system
Sometimes, it is necessary to power down all node canisters in a system. For example, you might need to shut down the system before you do the maintenance actions in your data center.
Before you begin
Notes:
- It is not necessary to shut down the entire system (all node canisters) when you complete service actions.
- Service actions upon a node canister require only one node canister in the control enclosure to be shut down. If one node canister of an I/O group is online and communicating with hosts and other nodes, volumes that depend on resources of the I/O group can remain online.
- Service actions upon a control enclosure might require the control enclosure to be shut down. In this case, the I/O group that is provided by the control enclosure goes offline. All volumes that depend on that I/O group become disabled. However, other I/O groups in the system can continue to operate.
Procedure
- Stop all host I/O to volumes on the system.
- Shut down the system by using the management GUI. Click Monitoring > System Hardware. From the System Actions menu, select Power Off System.
-
Wait for the shutdown operation to complete. When complete, the power LED on each node
canister, which is shown in Figure 1, blinks
at a 1 Hz rate (slow flash). Refer to the LEDs page for details.
Figure 1. Canister power LED location 
- 1 Canister power LED

- 1 Canister power LED
-
Disconnect the power cords.
-
If you are servicing the control enclosure only, disconnect the power cords from both power
supply units (PSUs) in the control enclosure.
Note: You do not need to power off the expansion enclosures.
-
If you are preparing for site maintenance, disconnect the power cords from both power supplies
in each expansion enclosure in the control enclosure's SAS chains.
Note: The 2U and 5U expansion enclosures do not have a power button. Each expansion enclosure has two PSUs.
-
If you are servicing the control enclosure only, disconnect the power cords from both power
supply units (PSUs) in the control enclosure.
- When you are ready to restore power to the control enclosure and any expansion enclosures, follow the appropriate procedures for your system configuration.