fence_scsi(8)

fence_scsi - Fence agent for SCSI persistent reservation

Section 8 fence-agents bookworm source

Description

FENCE_AGENT

NAME

fence_scsi - Fence agent for SCSI persistent reservation

DESCRIPTION

fence_scsi is an I/O fencing agent that uses SCSI-3 persistent reservations to control access to shared storage devices. These devices must support SCSI-3 persistent reservations (SPC-3 or greater) as well as the "preempt-and-abort" subcommand. The fence_scsi agent works by having each node in the cluster register a unique key with the SCSI device(s). Reservation key is generated from "node id" (default) or from "node name hash" (RECOMMENDED) by adjusting "key_value" option. Using hash is recommended to prevent issues when removing nodes from cluster without full cluster restart. Once registered, a single node will become the reservation holder by creating a "write exclusive, registrants only" reservation on the device(s). The result is that only registered nodes may write to the device(s). When a node failure occurs, the fence_scsi agent will remove the key belonging to the failed node from the device(s). The failed node will no longer be able to write to the device(s). A manual reboot is required.

When used as a watchdog device you can define e.g. retry=1, retry-sleep=2 and verbose=yes parameters in /etc/sysconfig/stonith if you have issues with it failing.

fence_scsi accepts options on the command line as well as from stdin. Fenced sends parameters through stdin when it execs the agent. fence_scsi can be run by itself with command line options. This is useful for testing and for turning outlets on or off from scripts.

Vendor URL:

PARAMETERS

-o, --action=[action]

Fencing action (Default Value: off)

-a, --aptpl

Use the APTPL flag for registrations. This option is only used for the ’on’ action.

-d, --devices=[devices]

List of devices to use for current operation. Devices can be comma-separated list of raw devices (eg. /dev/sdc). Each device must support SCSI-3 persistent reservations.

-k, --key=[key]

Key to use for the current operation. This key should be unique to a node. For the "on" action, the key specifies the key use to register the local node. For the "off" action, this key specifies the key to be removed from the device(s).

-n, --plug=[nodename]

Name of the node to be fenced. The node name is used to generate the key value used for the current operation. This option will be ignored when used with the -k option. This parameter is always required.

--readonly

Open DEVICE read-only.

--suppress-errors

Error log suppression.

-f, --logfile

Log output (stdout and stderr) to file

-q, --quiet

Disable logging to stderr. Does not affect --verbose or --debug-file or logging to syslog.

-v, --verbose

Verbose mode. Multiple -v flags can be stacked on the command line (e.g., -vvv) to increase verbosity.

--verbose-level

Level of debugging detail in output. Defaults to the number of --verbose flags specified on the command line, or to 1 if verbose=1 in a stonith device configuration (i.e., on stdin).

-D, --debug-file=[debugfile]

Write debug information to given file

-V, --version

Display version information and exit

-h, --help

Display help and exit

--plug-separator=[char]

Separator for plug parameter when specifying more than 1 plug (Default Value: ,)

--delay=[seconds]

Wait X seconds before fencing is started (Default Value: 0)

--disable-timeout=[true/false]

Disable timeout (true/false) (default: true when run from Pacemaker 2.0+)

--login-timeout=[seconds]

Wait X seconds for cmd prompt after login (Default Value: 5)

--power-timeout=[seconds]

Test X seconds for status change after ON/OFF (Default Value: 20)

--power-wait=[seconds]

Wait X seconds after issuing ON/OFF (Default Value: 0)

--shell-timeout=[seconds]

Wait X seconds for cmd prompt after issuing command (Default Value: 3)

--stonith-status-sleep=[seconds]

Sleep X seconds between status calls during a STONITH action (Default Value: 1)

--retry-on=[attempts]

Count of attempts to retry power on (Default Value: 1)

--corosync-cmap-path=[path]

Path to corosync-cmapctl binary (Default Value: /usr/sbin/corosync-cmapctl)

--key-value=<id|hash>

Method used to generate the SCSI key. "id" (default) uses the positional ID from "corosync-cmactl nodelist" output which can get inconsistent when nodes are removed from cluster without full cluster restart. "hash" uses part of hash made out of node names which is not affected over time but there is theoretical chance that hashes can collide as size of SCSI key is quite limited. (Default Value: id)

--sg_persist-path=[path]

Path to sg_persist binary (Default Value: /usr/bin/sg_persist)

--sg_turs-path=[path]

Path to sg_turs binary (Default Value: /usr/bin/sg_turs)

--vgs-path=[path]

Path to vgs binary (Default Value: /sbin/vgs)

ACTIONS

on

Power on machine.

off

Power off machine.

status

This returns the status of the plug/virtual machine.

monitor

Check the health of fence device

metadata

Display the XML metadata describing this resource.

manpage

The operational behavior of this is not known.

validate-all

Validate if all required parameters are entered.

STDIN PARAMETERS

action

Fencing action (Default Value: off)

aptpl

Use the APTPL flag for registrations. This option is only used for the ’on’ action.

devices

List of devices to use for current operation. Devices can be comma-separated list of raw devices (eg. /dev/sdc). Each device must support SCSI-3 persistent reservations.

key

Key to use for the current operation. This key should be unique to a node. For the "on" action, the key specifies the key use to register the local node. For the "off" action, this key specifies the key to be removed from the device(s).

plug

Name of the node to be fenced. The node name is used to generate the key value used for the current operation. This option will be ignored when used with the -k option. This parameter is always required. Obsoletes: port

readonly

Open DEVICE read-only.

suppress_errors

Error log suppression. Obsoletes: suppress-errors

logfile

Log output (stdout and stderr) to file

quiet

Disable logging to stderr. Does not affect --verbose or --debug-file or logging to syslog.

verbose

Verbose mode. Multiple -v flags can be stacked on the command line (e.g., -vvv) to increase verbosity.

verbose_level

Level of debugging detail in output. Defaults to the number of --verbose flags specified on the command line, or to 1 if verbose=1 in a stonith device configuration (i.e., on stdin).

debug_file

Write debug information to given file Obsoletes: debug

version

Display version information and exit

help

Display help and exit

plug_separator

Separator for plug parameter when specifying more than 1 plug (Default Value: ,)

delay

Wait X seconds before fencing is started (Default Value: 0)

disable_timeout

Disable timeout (true/false) (default: true when run from Pacemaker 2.0+)

login_timeout

Wait X seconds for cmd prompt after login (Default Value: 5)

power_timeout

Test X seconds for status change after ON/OFF (Default Value: 20)

power_wait

Wait X seconds after issuing ON/OFF (Default Value: 0)

shell_timeout

Wait X seconds for cmd prompt after issuing command (Default Value: 3)

stonith_status_sleep

Sleep X seconds between status calls during a STONITH action (Default Value: 1)

retry_on

Count of attempts to retry power on (Default Value: 1)

corosync_cmap_path

Path to corosync-cmapctl binary (Default Value: /usr/sbin/corosync-cmapctl)

key_value

Method used to generate the SCSI key. "id" (default) uses the positional ID from "corosync-cmactl nodelist" output which can get inconsistent when nodes are removed from cluster without full cluster restart. "hash" uses part of hash made out of node names which is not affected over time but there is theoretical chance that hashes can collide as size of SCSI key is quite limited. (Default Value: id)

sg_persist_path

Path to sg_persist binary (Default Value: /usr/bin/sg_persist)

sg_turs_path

Path to sg_turs binary (Default Value: /usr/bin/sg_turs)

vgs_path

Path to vgs binary (Default Value: /sbin/vgs)