IBM DS3950, Installation, User'S, And Maintenance Manual, Page: 143 / 252

v
Yes - Go to step 4.
v
No - Perform the procedure “Troubleshooting the storage subsystem ” on
page 101 to verify that the power supplies have shut down because of an
overheating problem, and then go to step 4.
4. Stop I/O activity to the storage subsystem and all attached storage expansion
enclosures.
5. Take all or some of the following measures to alleviate the overheating
problem:
v Removing all panels from the cabinet immediately
v
Using external fans to cool the area
v
Shutting down the power to the storage expansion enclosure, using the
procedure described in “Performing an emergency shutdown” on page 112
6. Wait for the air temperature in and around the storage subsystem to cool.
After the temperature inside the power supplies cools to below 65° C (149° F),
the storage subsystem is capable of power-up recovery without operator
intervention. After the air has cooled, the power supplies turn on
automatically. If the power supplies restart automatically, the controllers will
reset and return to normal operation.
7. Did the power supply and fan units restart automatically?
v
Yes - Go to step 9.
v No - Go to step 8.
8. Turn off the power switch on each controller in the storage subsystem, power
off all connected storage expansion enclosures, and flip the disconnected
devices to the OFF position. Wait 1 minute and then turn on power to all
connected storage expansion enclosures and flip the disconnected devices to
the ON position.
CAUTION:
This unit has more than one power source. To remove all power from the
unit, all MAINS must be disconnected.
CAUTION:
The power switch on the power supply and fan unit does not turn off the
electrical current supplied to the device. The DS3950 storage subsystem
might also have more than one connection to power. To remove all electrical
current from the device, ensure that all power cords are disconnected from
the power supply and fan unit input connectors.
While the storage expansion enclosure powers up, the LEDs on the front and
the back of the module flash intermittently. Depending on your configuration,
the storage expansion enclosure can take between 20 seconds and several
minutes to power on.
9. Turn on both power switches on the back of the storage subsystem.
A storage subsystem can take 10 seconds to power on and up to 15 minutes
for the battery self-test to complete. During this time, the LEDs on the front
and the back of the modules flash intermittently.
Chapter 4. Operating the storage subsystem
115