Section: Maintenance Commands (8)
Updated: Thu May 10 2001
Index Return to Main Contents


fos - failover services daemon to control the Red Hat clustering services.  


fos [-c cfgfile|--configfile=cfgfile] [-n|--nodaemon] [--nofork] [-t|--test-start] [-v|--verbose] [-f|--monitor] [-F|--active] [-?|--help] [--usage] [--version]  


fos reads the failover services section in the cluster configuration file The program must be run with either "--monitor" or "--active" (or -f and -F) specified. If "--monitor" is used, the program starts nanny daemons to monitor IP services on a partner system. If "--active" is specified, the program starts the IP services on the local system by executing startup scripts. In both cases, a service failure or child daemon exiting will cause fos to terminate, which in turn will notify pulse that something failed and to initiate a cluster failover.

fos is normally started by pulse although it can be run as a command line tool. Similarly, the configuration file that tells fos what to do is normally edited by piranha, but it can be manually edited.

All activity from fos is logged to syslog (when fos is running as a daemon).  


-c cfgfile|--configfile=cfgfile
Normally, fos uses as its configuration file, but this can be overridden and another file can be used.
Normally, fos runs as a daemon, however using this option, fos runs in the foreground. When running in this mode, all its output is sent to STDOUT instead of syslog.
Don't fork, but do perform disassociate.
Running fos is test mode allows the user to monitor what fos would actually do. This is only useful during debugging.
Display additional debugging information as it runs.
Start and control nanny daemons that will monitor services (defined in the file) on a partner computer system. Either this option, or "-F|--active" must be specified.
Start the IP services (defined in the file) on the local system using scripts. Either this option or "-f|--monitor" must be specified.
Shows a verbose usage listing.
Outputs a terse argument summary.
Print program version.



ipvsadmn(8) lvsd(8) nanny(8) pulse(8) send_arp(8)



Keith Barrett <>



AUTHOR manual pages