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.
- The preferred way to disable ACPI Soft-Off is to change the BIOS setting to "instant-off" or an equivalent setting that turns off the node without delay, as described in Section 5.11.1, “Disabling ACPI Soft-Off with the BIOS”.
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=ignorein the/etc/systemd/logind.conffile 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=offto 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.
- Reboot the node and start the
BIOS CMOS Setup Utilityprogram. - Navigate to the menu (or equivalent power management menu).
- At the menu, set the function (or equivalent) to (or the equivalent setting that turns off the node by means of the power button without delay). Example 5.1, “
BIOS CMOS Setup Utility: set to ” shows a menu with set to and set to .Note
The equivalents to , , and 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. - Exit the
BIOS CMOS Setup Utilityprogram, saving the BIOS configuration. - 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: set to
+---------------------------------------------|-------------------+ | 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 set to , and set to .
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.
- Define the following configuration in the
/etc/systemd/logind.conffile:HandlePowerKey=ignore
- Reload the
systemdconfiguration:#
systemctl daemon-reload - 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:
- Use the
--argsoption in combination with the--update-kerneloption of thegrubbytool to change thegrub.cfgfile of each cluster node as follows:#
grubby --args=acpi=off --update-kernel=ALLFor general information on GRUB 2, see the Working with GRUB 2 chapter in the System Administrator's Guide. - Reboot the node.
- Verify that the node turns off immediately when fenced. For information on testing a fence device, see Section 5.12, “Testing a Fence Device”.
