How do I list and test available watchdog devices to use with SBD in a RHEL 8 Pacemaker cluster?

Solution Verified - Updated

Environment

  • Red Hat Enterprise Linux (RHEL) 8 with the High Availability Add-on

Issue

  • Which watchdog devices can I use with SBD, and how do I test them?

Resolution

Listing watchdog devices


Use the `pcs stonith sbd watchdog list` command to print a list of available watchdog devices. 
# pcs stonith sbd watchdog list
Available watchdog(s):
  /dev/watchdog
  /dev/watchdog0
  /dev/watchdog1

For more information on the identity and settings of each watchdog, use the wdctl command. Note that /dev/watchdog0 should point to the same physical device as /dev/watchdog.

# wdctl
Device:        /dev/watchdog
Identity:      i6300ESB timer [version 0]
Timeout:       30 seconds
Pre-timeout:    0 seconds
FLAG           DESCRIPTION               STATUS BOOT-STATUS
KEEPALIVEPING  Keep alive ping reply          1           0
MAGICCLOSE     Supports magic close char      1           0
SETTIMEOUT     Set timeout (in seconds)       0           0
 
# wdctl /dev/watchdog0
Device:        /dev/watchdog0
Identity:      i6300ESB timer [version 0]
Timeout:       30 seconds
Pre-timeout:    0 seconds
FLAG           DESCRIPTION               STATUS BOOT-STATUS
KEEPALIVEPING  Keep alive ping reply          1           0
MAGICCLOSE     Supports magic close char      0           0
SETTIMEOUT     Set timeout (in seconds)       0           0

# wdctl /dev/watchdog1
Device:        /dev/watchdog1
Identity:      Software Watchdog [version 0]
Timeout:       60 seconds
Pre-timeout:    0 seconds
FLAG           DESCRIPTION               STATUS BOOT-STATUS
KEEPALIVEPING  Keep alive ping reply          1           0
MAGICCLOSE     Supports magic close char      1           0
SETTIMEOUT     Set timeout (in seconds)       0           0

Note that as of RHEL 8.1, softdog is not supported for use with SBD.

Testing watchdog devices


Use the `pcs stonith sbd watchdog test` command to test a watchdog device. If this works properly, it should force a reset of the machine. 
Usage: pcs stonith sbd watchdog test...
    sbd watchdog test [<watchdog-path>]
        This operation is expected to force-reboot the local system without
        following any shutdown procedures using a watchdog. If no watchdog is
        specified, available watchdog will be used if only one watchdog device
        is available on the local system.

Note that by specifying a <watchdog-path>, you can test any available watchdog. This command can also be run without a <watchdog-path> to use the available watchdog if only one is available.

# pcs stonith sbd watchdog test
Warning: This operation is expected to force-reboot this system without following any shutdown procedures.
Proceed? [no/yes]: yes
System will reset shortly
Error: Multiple watchdog devices available, therefore, watchdog which should be tested has to be specified. To list available watchdog devices use command 'pcs stonith sbd watchdog list'

# pcs stonith sbd watchdog test /dev/watchdog
Warning: This operation is expected to force-reboot this system without following any shutdown procedures.
Proceed? [no/yes]: yes
System will reset shortly

Root Cause

RHEL 8 adds a new pcs stonith sbd watchdog subcommand to list and test available watchdog devices for SBD.

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