5.11. Configuring ACPI For Use with Integrated Fence Devices

If your cluster uses integrated fence devices, you must configure ACPI (Advanced Configuration and Power Interface) to ensure immediate and complete fencing.
If a cluster node is configured to be fenced by an integrated fence device, disable ACPI Soft-Off for that node. Disabling ACPI Soft-Off allows an integrated fence device to turn off a node immediately and completely rather than attempting a clean shutdown (for example, shutdown -h now). Otherwise, if ACPI Soft-Off is enabled, an integrated fence device can take four or more seconds to turn off a node (see the note that follows). In addition, if ACPI Soft-Off is enabled and a node panics or freezes during shutdown, an integrated fence device may not be able to turn off the node. Under those circumstances, fencing is delayed or unsuccessful. Consequently, when a node is fenced with an integrated fence device and ACPI Soft-Off is enabled, a cluster recovers slowly or requires administrative intervention to recover.

Note

The amount of time required to fence a node depends on the integrated fence device used. Some integrated fence devices perform the equivalent of pressing and holding the power button; therefore, the fence device turns off the node in four to five seconds. Other integrated fence devices perform the equivalent of pressing the power button momentarily, relying on the operating system to turn off the node; therefore, the fence device turns off the node in a time span much longer than four to five seconds.
Disabling ACPI Soft-Off with the BIOS may not be possible with some systems. If disabling ACPI Soft-Off with the BIOS is not satisfactory for your cluster, you can disable ACPI Soft-Off with one of the following alternate methods:
  • Setting HandlePowerKey=ignore in the /etc/systemd/logind.conf file and verifying that the node node turns off immediately when fenced, as described in Section 5.11.2, “Disabling ACPI Soft-Off in the logind.conf file”. This is the first alternate method of disabling ACPI Soft-Off.
  • Appending acpi=off to the kernel boot command line, as described in Section 5.11.3, “Disabling ACPI Completely in the GRUB 2 File”. This is the second alternate method of disabling ACPI Soft-Off, if the preferred or the first alternate method is not available.

    Important

    This method completely disables ACPI; some computers do not boot correctly if ACPI is completely disabled. Use this method only if the other methods are not effective for your cluster.

5.11.1. Disabling ACPI Soft-Off with the BIOS

You can disable ACPI Soft-Off by configuring the BIOS of each cluster node with the following procedure.

Note

The procedure for disabling ACPI Soft-Off with the BIOS may differ among server systems. You should verify this procedure with your hardware documentation.
  1. Reboot the node and start the BIOS CMOS Setup Utility program.
  2. Navigate to the Power menu (or equivalent power management menu).
  3. At the Power menu, set the Soft-Off by PWR-BTTN function (or equivalent) to Instant-Off (or the equivalent setting that turns off the node by means of the power button without delay). Example 5.1, “BIOS CMOS Setup Utility: Soft-Off by PWR-BTTN set to Instant-Off shows a Power menu with ACPI Function set to Enabled and Soft-Off by PWR-BTTN set to Instant-Off.

    Note

    The equivalents to ACPI Function, Soft-Off by PWR-BTTN, and Instant-Off may vary among computers. However, the objective of this procedure is to configure the BIOS so that the computer is turned off by means of the power button without delay.
  4. Exit the BIOS CMOS Setup Utility program, saving the BIOS configuration.
  5. Verify that the node turns off immediately when fenced. For information on testing a fence device, see Section 5.12, “Testing a Fence Device”.

Example 5.1. BIOS CMOS Setup Utility: Soft-Off by PWR-BTTN set to Instant-Off

+---------------------------------------------|-------------------+
|    ACPI Function             [Enabled]      |    Item Help      |
|    ACPI Suspend Type         [S1(POS)]      |-------------------|
|  x Run VGABIOS if S3 Resume   Auto          |   Menu Level   *  |
|    Suspend Mode              [Disabled]     |                   |
|    HDD Power Down            [Disabled]     |                   |
|    Soft-Off by PWR-BTTN      [Instant-Off   |                   |
|    CPU THRM-Throttling       [50.0%]        |                   |
|    Wake-Up by PCI card       [Enabled]      |                   |
|    Power On by Ring          [Enabled]      |                   |
|    Wake Up On LAN            [Enabled]      |                   |
|  x USB KB Wake-Up From S3     Disabled      |                   |
|    Resume by Alarm           [Disabled]     |                   |
|  x  Date(of Month) Alarm       0            |                   |
|  x  Time(hh:mm:ss) Alarm       0 :  0 :     |                   |
|    POWER ON Function         [BUTTON ONLY   |                   |
|  x KB Power ON Password       Enter         |                   |
|  x Hot Key Power ON           Ctrl-F1       |                   |
|                                             |                   |
|                                             |                   |
+---------------------------------------------|-------------------+
This example shows ACPI Function set to Enabled, and Soft-Off by PWR-BTTN set to Instant-Off.

5.11.2. Disabling ACPI Soft-Off in the logind.conf file

To disable power-key handing in the /etc/systemd/logind.conf file, use the following procedure.
  1. Define the following configuration in the /etc/systemd/lodingd.conf file:
    HandlePowerKey=ignore
    
  2. Reload the systemd configuration:
    # systemctl daemon-reload
  3. Verify that the node turns off immediately when fenced. For information on testing a fence device, see Section 5.12, “Testing a Fence Device”.

5.11.3. Disabling ACPI Completely in the GRUB 2 File

You can disable ACPI Soft-Off by appending acpi=off to the GRUB menu entry for a kernel.

Important

This method completely disables ACPI; some computers do not boot correctly if ACPI is completely disabled. Use this method only if the other methods are not effective for your cluster.
Use the following procedure to disable ACPI in the GRUB 2 file:
  1. Use the --args option in combination with the --update-kernel option of the grubby tool to change the grub.cfg file of each cluster node as follows:
    # grubby --args=acpi=off --update-kernel=ALL
    For general information on GRUB 2, see the Working with GRUB 2 chapter in the System Administrator's Guide.
  2. Reboot the node.
  3. Verify that the node turns off immediately when fenced. For information on testing a fence device, see Section 5.12, “Testing a Fence Device”.