Troubleshooting Power Issues
If your storage server does not power on, the cause of the problem might be:
AC Power Connection
The AC power cords are the direct connection between the storage server power supplies and the power sources. The storage server power supplies need separate stable AC circuits. Insufficient voltage levels or fluctuations in power can cause storage server power problems. The power supplies are designed to operate at a particular voltage and within an acceptable range of voltage fluctuations (refer to Power Specifications in Oracle Exadata Storage Server X5-2 Extreme Flash Installation Guide).
Action: Check that both AC power cords are connected to the storage server. Check that the correct power is present at the outlets and monitor the power to verify that it is within the acceptable range. You can verify proper connection and operation by checking the power supply (PS) indicator panels, which are located at the back of the storage server on the power supplies. Lit green AC OK indicators show a properly functioning power supply. An amber AC OK indicator indicates that the AC power to the power supply is insufficient.
Prevention: Use the AC power cord Velcro retaining clips and position the cords to minimize the risk of accidental disconnection. Ensure that the AC circuits that supply power to the storage server are stable and not overburdened.
Power Supplies (PSUs)
The storage server power supplies (PSUs) provide the necessary storage server voltages from the AC power outlets. If the power supplies are inoperable, unplugged, or disengaged from the internal connectors, the storage server cannot power on.
Note - The Velcro straps shown in the following figure should be used to secure the power cord connectors to the rear of the power supplies. The Velcro retaining straps minimize the risk of accidental disconnection.
Action: Check that the AC cables are connected to both power supplies. Check that the power supplies are operational (the PSU indicator panel should have a lit green AC OK indicator). Ensure that the power supply is properly installed. A power supply that is not fully engaged with its internal connector does not have power applied and does not have a lit green AC OK indicator.
Prevention: When a power supply fails, replace it immediately. To ensure redundancy, the storage server has two power supplies. This redundant configuration prevents storage server downtime, or an unexpected shutdown, due to a failed power supply. The redundancy allows the storage server to continue to operate if one of the power supplies fails. However, when a storage server is being powered by a single power supply, the redundancy no longer exists, and the risk for downtime or an unexpected shutdown increases. When installing a power supply, ensure that it is fully seated and engaged with its connector inside the drive bay. A properly installed power supply has a lit green AC OK indicator.
Top Cover
The storage server top cover is an important component for a properly functioning storage server. The top cover is vital to the storage server cooling subsystem because it helps to maintain the pressure areas within the storage server, and the top cover also protects against accidental exposure to hazardous voltages and damage to internal components. For these reasons, the storage server top cover is interlocked to the storage server power. The interlock is created by a switch that is mounted inside the storage server on the housing for the power supply. The switch engages when the cover is installed, allowing power to be applied to the storage server. When the cover is not installed, the storage server cannot power on. If the storage server is powered on when the cover is removed, power is immediately switched off.
Action: If the storage server does not power on, check that the switch is intact and properly aligned. Ensure that the storage server top cover is in place and sits flat and snug on top of the storage server. Ensure that the interlock switch components have not been damaged, removed, or misaligned. For instructions for properly installing the top cover, see Install the Storage Server Top Cover.
Prevention: After removing the top cover, take care that it does not get bent. When servicing the storage server, take care that the internally mounted interlock switch component does not get damaged or misaligned. Never operate the storage server without the top cover installed.