Powering on and powering off the clustered system

To power on or to power off the system, complete the steps in this procedure in the order given.

Powering on the system

Power on the Fibre Channel switches.
Power on external storage systems.
Power on SAN Volume Controller nodes.
Power on expansion enclosures.
Start hosts.

Before you power off the system

To remove all input power to a system (for example, the machine room power must be shut down for maintenance), you must shut down the system before power is removed. Shutting down the system causes all nodes in the system to store data to the internal drive and then enter a standby state. In standby state, volumes provided by the system are no longer accessible.

If the system is not shut down before power to the nodes is turned off, the nodes detect the loss of power and continue to run on battery power until all data that is held in memory is saved to the internal drive.

When input power is restored to the enclosures, the batteries in the nodes recharge. However, the nodes do not permit any I/O activity until the batteries have sufficient charge to enable all the data on the nodes to be saved in the event of an unexpected power loss. This might take as long as two hours if the batteries have been discharged because nodes have run on battery power. Shutting down the system prior to removing input power to the batteries prevents the battery power from being drained and makes it possible for I/O activity to resume as soon as input power is restored.

Powering off the system

Stop hosts.
Shut down the clustered system by using the management GUI. Click Monitoring > System. In the Actions menu, select Power off.
Note: You can use the front panel to shut down nodes individually; however, this is not advisable. Some node models, such as the SAN Volume Controller 2145-DH8, do not have a front panel display.
Power off the expansion enclosure.
(Optional) Shut down external storage systems.
(Optional) Shut down Fibre Channel switches.

Important: If you power off a SAN Volume Controller 2145-DH8 node and might not power it back on the same day, follow these steps to prevent the batteries from being discharged too much while the node is connected to power but not powered on:

Pull both batteries out of the node. Keep them out until you're ready to power on the node.
Push the batteries in just before you press the power button to power on the node.

If you disconnect the power from a SAN Volume Controller 2145-DH8 node and might not reconnect power to it again within the next 24 hours, follow these steps to prevent the batteries from being discharged too much while the node is not connected to power:

After both power cords are disconnected from the node, pull both batteries out of the node. This step completely turns off the battery backplane.
Push the batteries back in again.