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mfsmaster

Start, restart or stop MooseFS master process.

This page reproduces the manual page mfsmaster(8) as the product ships it: the text man mfsmaster prints on a machine where the packages are installed. It is not edited here, and where it disagrees with the rest of this documentation, the documentation is the side kept against the sources. What the subject is: Command line tools.

Synopsis​

mfsmaster [-f] [-d] [-u] [-n] [-t LOCKTIMEOUT] [-c CFGFILE] [-o OPTIONOVERRIDE] [-i] [-a] [-e] [-x[x]] [ACTION]

mfsmaster -v

mfsmaster -h

Description​

mfsmaster is the master program of MooseFS.

Options​

  • -v
    print version information and exit

  • -h
    print usage information and exit

  • -f
    run in foreground, don't daemonize

  • -d
    run with dangerous options (names: DANGEROUS_*)

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

  • -n
    do not attempt to increase limit of core dump size

  • -t LOCKTIMEOUT
    how long to wait for lockfile (in seconds; default is 1800 seconds)

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

  • -o OPTIONOVERRIDE
    override a config option - see NOTES

  • -i
    ignore some metadata structure errors

  • -a
    automatically restore metadata from change logs

  • -e
    (pro only) start without metadata (used to start additional masters)

  • -x
    produce more verbose output

  • -xx
    even more verbose output

  • ACTION
    tells master to perform one of the following actions:

    • start
      (default action) Start the master process if the process is not already running, otherwise display an error message.

    • stop
      Stop the master process if the process is running, otherwise display an error message.

    • restart
      If the master process is running, restart it, if it's not running, start it.

    • reload
      Send a signal to the master process to reload config files.

    • info
      Send a signal to the master process to dump debug information file in working directory.

    • test
      Displays "mfsmaster pid: PID" if the master is running (and return 0) or "mfsmaster is not running" otherwise (and return 1).

    • kill
      Send an immediate termination signal to master process.

    • restore
      Restore current metadata file using backup metadata and changelog files (if possible, i.e. if correct files exist), write it to working directory and exit.

Files​

  • mfsmaster.cfg
    configuration file for MooseFS master process; refer to mfsmaster.cfg(5) manual for details

  • mfsexports.cfg
    MooseFS access control file; refer to mfsexports.cfg(5) manual for details

  • mfstopology.cfg
    Network topology definitions; refer to mfstopology.cfg(5) manual for details

  • mfsipmap.cfg
    Chunkservers IP mapping definitions; refer to mfsipmap.cfg(5) manual for details

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

  • .bgwriter.lock
    lock file of running MooseFS master subprocess for storing metadata (created in data directory)

  • metadata.mfs, metadata\.mfs\.back
    MooseFS filesystem metadata image (created in data directory)

  • metadata.crc
    CRC of metadata.mfs file (created in data directory)

  • metadata.mfs.empty
    An empty metadata file, to be used when starting up a fresh MooseFS instance (created in data directory)

  • changelog.*.mfs
    MooseFS filesystem metadata change logs (created in data directory)

  • stats.mfs
    master charts stats (created in data directory)

  • .mfsmaster_info.txt
    master info file, created by sending the process INFO signal, with work parameters that can be used for debugging/support purposes (created in data directory)

Notes​

All MooseFS daemons, including mfsmaster, can read configuration options from 3 sources. These sources are, in order from the most important, to the least important:

  • option overrides provided in commandline as arguments
  • options defined in environment variables
  • options defined in the daemon's main config file (mfsmaster.cfg for mfsmaster process).

All possible configuration options are described in the manpage for the mfsmaster.cfg(5) file. Options provided in commandline are the same as in the config file (e.g. running the mfsmaster with -o INSTANCE_NAME=foobar will change the master name presented in GUI to "foobar"). Options provided in environment must be prefixed with "MFSCFG_" (e.g setting MFSCFG_INSTANCE_NAME to "foobar" in environment will change the master name presented in GUI to "foobar" if INSTANCE_NAME is not overriden in commandline).

See also​

mfschunkserver(8), mfsmount(8), mfsmaster.cfg(5), mfsexports.cfg(5), mfstopology.cfg(5)