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13.3. Special Treatment of STONITH Resources

STONITH resources are somewhat special in Pacemaker.
STONITH may be initiated by pacemaker or by other parts of the cluster (such as resources like DRBD or DLM). To accommodate this, pacemaker does not require the STONITH resource to be in the started state in order to be used, thus allowing reliable use of STONITH devices in such a case.

Note

In pacemaker versions 1.1.9 and earlier, this feature either did not exist or did not work well. Only "running" STONITH resources could be used by Pacemaker for fencing, and if another component tried to fence a node while Pacemaker was moving STONITH resources, the fencing could fail.
All nodes have access to STONITH devices' definitions and instantiate them on-the-fly when needed, but preference is given to verified instances, which are the ones that are started according to the cluster’s knowledge.
In the case of a cluster split, the partition with a verified instance will have a slight advantage, because the STONITH daemon in the other partition will have to hear from all its current peers before choosing a node to perform the fencing.
Fencing resources do work the same as regular resources in some respects:

Important

Currently there is a limitation that fencing resources may only have one set of meta-attributes and one set of instance attributes. This can be revisited if it becomes a significant limitation for people.
See the table below or run man stonithd to see special instance attributes that may be set for any fencing resource, regardless of fence agent.

Table 13.1. Properties of Fencing Resources

Field Type Default Description
stonith-timeout
NA
NA
Older versions used this to override the default period to wait for a STONITH (reboot, on, off) action to complete for this device. It has been replaced by the pcmk_reboot_timeout and pcmk_off_timeout properties.
priority
integer
0
The priority of the STONITH resource. Devices are tried in order of highest priority to lowest.
pcmk_host_map
string
A mapping of host names to ports numbers for devices that do not support host names. Example: node1:1;node2:2,3 tells the cluster to use port 1 for node1 and ports 2 and 3 for node2.
pcmk_host_list
string
A list of machines controlled by this device (optional unless pcmk_host_check is static-list).
pcmk_host_check
string
dynamic-list
How to determine which machines are controlled by the device. Allowed values:
  • dynamic-list: query the device
  • static-list: check the pcmk_host_list attribute
  • none: assume every device can fence every machine
pcmk_delay_max
time
0s
Enable a random delay of up to the time specified before executing stonith actions. This is sometimes used in two-node clusters to ensure that the nodes don’t fence each other at the same time.
pcmk_action_limit
integer
1
The maximum number of actions that can be performed in parallel on this device, if the cluster option concurrent-fencing is true. -1 is unlimited.
pcmk_host_argument
string
port
Advanced use only. Which parameter should be supplied to the resource agent to identify the node to be fenced. Some devices do not support the standard port parameter or may provide additional ones. Use this to specify an alternate, device-specific parameter. A value of none tells the cluster not to supply any additional parameters.
pcmk_reboot_action
string
reboot
Advanced use only. The command to send to the resource agent in order to reboot a node. Some devices do not support the standard commands or may provide additional ones. Use this to specify an alternate, device-specific command.
pcmk_reboot_timeout
time
60s
Advanced use only. Specify an alternate timeout to use for reboot actions instead of the value of stonith-timeout. Some devices need much more or less time to complete than normal. Use this to specify an alternate, device-specific timeout.
pcmk_reboot_retries
integer
2
Advanced use only. The maximum number of times to retry the reboot command within the timeout period. Some devices do not support multiple connections, and operations may fail if the device is busy with another task, so Pacemaker will automatically retry the operation, if there is time remaining. Use this option to alter the number of times Pacemaker retries before giving up.
pcmk_off_action
string
off
Advanced use only. The command to send to the resource agent in order to shut down a node. Some devices do not support the standard commands or may provide additional ones. Use this to specify an alternate, device-specific command.
pcmk_off_timeout
time
60s
Advanced use only. Specify an alternate timeout to use for off actions instead of the value of stonith-timeout. Some devices need much more or less time to complete than normal. Use this to specify an alternate, device-specific timeout.
pcmk_off_retries
integer
2
Advanced use only. The maximum number of times to retry the off command within the timeout period. Some devices do not support multiple connections, and operations may fail if the device is busy with another task, so Pacemaker will automatically retry the operation, if there is time remaining. Use this option to alter the number of times Pacemaker retries before giving up.
pcmk_list_action
string
list
Advanced use only. The command to send to the resource agent in order to list nodes. Some devices do not support the standard commands or may provide additional ones. Use this to specify an alternate, device-specific command.
pcmk_list_timeout
time
60s
Advanced use only. Specify an alternate timeout to use for list actions instead of the value of stonith-timeout. Some devices need much more or less time to complete than normal. Use this to specify an alternate, device-specific timeout.
pcmk_list_retries
integer
2
Advanced use only. The maximum number of times to retry the list command within the timeout period. Some devices do not support multiple connections, and operations may fail if the device is busy with another task, so Pacemaker will automatically retry the operation, if there is time remaining. Use this option to alter the number of times Pacemaker retries before giving up.
pcmk_monitor_action
string
monitor
Advanced use only. The command to send to the resource agent in order to report extended status. Some devices do not support the standard commands or may provide additional ones. Use this to specify an alternate, device-specific command.
pcmk_monitor_timeout
time
60s
Advanced use only. Specify an alternate timeout to use for monitor actions instead of the value of stonith-timeout. Some devices need much more or less time to complete than normal. Use this to specify an alternate, device-specific timeout.
pcmk_monitor_retries
integer
2
Advanced use only. The maximum number of times to retry the monitor command within the timeout period. Some devices do not support multiple connections, and operations may fail if the device is busy with another task, so Pacemaker will automatically retry the operation, if there is time remaining. Use this option to alter the number of times Pacemaker retries before giving up.
pcmk_status_action
string
status
Advanced use only. The command to send to the resource agent in order to report status. Some devices do not support the standard commands or may provide additional ones. Use this to specify an alternate, device-specific command.
pcmk_status_timeout
time
60s
Advanced use only. Specify an alternate timeout to use for status actions instead of the value of stonith-timeout. Some devices need much more or less time to complete than normal. Use this to specify an alternate, device-specific timeout.
pcmk_status_retries
integer
2
Advanced use only. The maximum number of times to retry the status command within the timeout period. Some devices do not support multiple connections, and operations may fail if the device is busy with another task, so Pacemaker will automatically retry the operation, if there is time remaining. Use this option to alter the number of times Pacemaker retries before giving up.