Which step must be performed before powering off a PowerStore appliance for maintenance?

The only officially supported method for gracefully powering down a PowerStore appliance is by using the "Shut Down" feature within PowerStore Manager. This procedure ensures that all system services are stopped in the correct order, all write caches are flushed to persistent storage, and both nodes are brought to a safe state before physical power is removed. Initiating the shutdown from the management interface is a mandatory step to prevent data loss or corruption that could occur from an improper or hard shutdown.

A. Disconnect all network cables This is incorrect. Network connectivity is required to access PowerStore Manager to initiate the graceful shutdown procedure. Cables should only be disconnected after the system is fully powered off.
B. Place the appliance in service mode This is incorrect. Service mode is a specific state for a node, not the entire appliance, used for performing certain hardware service tasks. It is not a prerequisite for a standard appliance shutdown.
D. Remove both power supplies This is incorrect. Removing power supplies is the final step of a physical power-off and must only be performed after the appliance has been gracefully shut down using PowerStore Manager.

1. Dell PowerStore Manager Administrator’s Guide for PowerStoreOS 3.6, Page 101, "Shut down the system": "Use this procedure to shut down the cluster. When you shut down the cluster, both nodes in all the appliances in the cluster are powered off." The guide then details the step-by-step process exclusively through the PowerStore Manager UI.

2. Dell PowerStore Hardware Information Guide, Page 28, "Powering off the system": "Use PowerStore Manager to shut down the system. This is the only supported method for shutting down the system." This statement explicitly confirms that using PowerStore Manager is the mandatory and sole supported procedure.

3. Dell PowerStore Service Concepts Guide for PowerStoreOS 3.5, Page 10, "Service mode": "Service mode is a system state that allows you to perform service operations on the hardware components of a PowerStore cluster... Before you can perform a service operation on a hardware component, you must place the associated node in service mode." This clarifies that service mode is for specific component-level hardware maintenance on a single node, not for a full appliance shutdown.