Provided by: lizardfs-master_3.9.4+dfsg-4_i386 bug

NAME

       mfsmaster - start, restart or stop Lizard File System metadata server
       process

SYNOPSIS

       mfsmaster [-f] [-c CFGFILE] [-u] [-d] [-t LOCKTIMEOUT] [ACTION]

       mfsmaster -s [-c CFGFILE]

       mfsmaster -v

       mfsmaster -h

DESCRIPTION

       mfsmaster is the metadata server program of Lizard File System.
       Depending on parameters it can start, restart or stop LizardFS metadata
       server process. Without any options it starts LizardFS metadata server,
       killing previously run process if lock file exists.

       Metadata server can work in one of two modes (personalities):

        1. master

        2. shadow

       If metadata server works with master personality it acts as main
       metadata server govering all file system metadata modifications. If
       metadata server works with shadow personality it acts as backup
       metadata server ready for immediate deployment as new master in case of
       current master failure. Shadow only accepts connections from
       lizardfs-admin, i.e. mfschunkserver, mfsmetalogger and mfsmount (the
       client) are not allowed to connect to shadow instance.

       Current metadata server personality is defined in metadata server
       configuration file and can be changed on the fly from shadow to master
       by proper modification and reloading of its configuration file.

       Master and shadow are designed to run simultaneously in sync forever.
       It is very unlikely but still (due to a memory corruption or a bug)
       possible that after some time their metadata will somehow differ. Since
       version 2.5.2 metadata checksum is maintained both by master and
       shadow, in order to detect and fix possible metadata corruptions. In
       case mismatch is detected shadow asks master to double check its
       metadata and dump its current snapshot. After the metadata is dumped
       and the checksum in master is recalculated shadow downloads the new
       metadata snapshot, which should ensure that master and all shadows have
       exactly the same metadata.

       SIGHUP (or reload ACTION) forces mfsmaster to reload all configuration
       files.

       -v
           print version information and exit

       -h
           print usage information and exit

       -f
           (deprecated, use start action instead) forcily run LizardFS master
           process, without trying to kill previous instance (this option
           allows to run LizardFS master if stale PID file exists)

       -s
           (deprecated, use stop action instead) stop LizardFS master process

       -c CFGFILE
           specify alternative path of configuration file (default is
           mfsmaster.cfg in system configuration directory)

       -u
           log undefined configuration values (when default is assumed)

       -d
           run in foreground, don’t daemonize

       -t LOCKTIMEOUT
           how long to wait for lockfile (default is 60 seconds)

       ACTION
           is the one of start, stop, restart, reload, test, isalive or kill.
           Default action is restart.

FILES

       mfsmaster.cfg
           configuration file for LizardFS master process (see
           mfsmaster.cfg(5) manual)

       mfsexports.cfg
           LizardFS access control file (used with mfsmounts 1.6.0 or later,
           see mfsexports.cfg(5) manual)

       mfstopology.cfg
           Network topology definitions (see mfstopology.cfg(5) manual)

       mfsmaster.lock
           PID file of running LizardFS master process

       .mfsmaster.lock
           lock file of running LizardFS master process (created in data
           directory)

       metadata.mfs, metadata.mfs.back
           LizardFS filesystem metadata image

       changelog.*.mfs
           LizardFS filesystem metadata change logs (merged into metadata.mfs
           once per hour)

       data.stats
           LizardFS master charts state

REPORTING BUGS

       Report bugs to <contact@lizardfs.org>.

COPYRIGHT

       Copyright 2008-2009 Gemius SA, 2013-2015 Skytechnology sp. z o.o.

       LizardFS is free software: you can redistribute it and/or modify it
       under the terms of the GNU General Public License as published by the
       Free Software Foundation, version 3.

       LizardFS is distributed in the hope that it will be useful, but WITHOUT
       ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
       FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
       for more details.

       You should have received a copy of the GNU General Public License along
       with LizardFS. If not, see http://www.gnu.org/licenses/.

SEE ALSO

       mfsmetarestore(8), mfschunkserver(8), mfsmount(1), mfsmaster.cfg(5),
       mfsexports.cfg(5), mfstopology.cfg(5), moosefs(7)

                                  02/16/2016                      MFSMASTER(8)