Enabling the override parameter – HP IO Accelerator for BladeSystem c-Class User Manual

Page 15

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Enabling full slot power draw—Some PCIe slots provide additional power (often up to 75 W of power).

If your PCIe slot is rated to provide at least 55 W, then you can allow the device to draw full power from

the PCIe slot by setting a VSL module parameter. For more information on enabling this override
parameter, see "Enabling the override parameter (on page

15

)."

CAUTION:

If the PCIe slot is not capable of providing the needed amount of power, then

enabling full power draw from the PCIe slot might result in malfunction or even damage to server

hardware. The user is responsible for any damage to equipment due to improper use of the

override parameter. HP expressly disclaims any liability for damage arising from improper use of
the override parameter. To confirm the power limits and capabilities of each slot, as well as the

entire system, contact the server manufacturer. For information about using the override

parameter, contact HP Customer Support.

NOTE:

The override parameter overrides the setting that prevents devices from drawing more

than 25 W from the PCIe slot. The parameter is enabled by device using the device serial

numbers. Once the setting is overridden, each device might draw up to the full 55 W needed for
peak performance.

Before you enable the override parameter, ensure that each PCIe slot is rated to provide enough power
for all slots, devices, and server accessories. To determine the power slot limits, consult the server
documentation, BIOS interface, setup utility, or use the fio-pci-check command.

Important considerations

If you are installing more than one dual IO Accelerator device and enabling the override parameter for
each device, be sure the motherboard is rated to provide 55W power to each slot used. For example,

some motherboards safely provide up to 75W to any one slot, but run into power constraints when

multiple slots are used to provide that much power. Installing multiple devices in this situation might
result in server hardware damage. Consult with the manufacturer to determine the total PCIe slot power

available.

The override parameter persists in the system and enables full power draw on an enabled device even
if the device is removed and then placed in a different slot within the same system. If the device is placed

in a slot that is not rated to provide 55W of power, your server hardware could experience a power

drag.

The override parameter is a setting for the IO Accelerator VSL software by server and is not stored in the

device. When moved to a new server, the device defaults to the 25 W power limit until an external
power cable is added or the override parameter is enabled for that device in the new server. To

determine the total PCIe slot power available for the new server, consult the manufacturer.

Enabling the override parameter

1.

Use one of the following methods to determine the serial number of each device to be installed in a
compatible slot:

o

Enter the fio-status command:
Sample output:
fio-status
...
Adapter: Dual Controller Adapter
Fusion-io ioDrive2 DUO 2.41TB, Product Number:F01-001-2T41-CS-0001, FIO
SN:1149D0969

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