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. Fencing action Use the APTPL flag for registrations. This option is only used for the 'on' action. 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 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). 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. 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. Open DEVICE read-only. Error log suppression. Error log suppression. Log output (stdout and stderr) to file Disable logging to stderr. Does not affect --verbose or --debug-file or logging to syslog. Verbose mode. Multiple -v flags can be stacked on the command line (e.g., -vvv) to increase verbosity. 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). Write debug information to given file Write debug information to given file Display version information and exit Display help and exit Separator for plug parameter when specifying more than 1 plug Wait X seconds before fencing is started Disable timeout (true/false) (default: true when run from Pacemaker 2.0+) Wait X seconds for cmd prompt after login Test X seconds for status change after ON/OFF Wait X seconds after issuing ON/OFF Wait X seconds for cmd prompt after issuing command Sleep X seconds between status calls during a STONITH action Count of attempts to retry power on Path to corosync-cmapctl binary 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. Path to sg_persist binary Path to sg_turs binary Path to vgs binary