initdb — create a new PostgreSQL database cluster
initdb [option...]  [ --pgdata  |   -D ] directory 
   initdb creates a new
   PostgreSQL database cluster.
  
   Creating a database cluster consists of creating the
   directories in
   which the cluster data will live, generating the shared catalog
   tables (tables that belong to the whole cluster rather than to any
   particular database), and creating the postgres,
   template1, and template0 databases.
   The postgres database is a default database meant
   for use by users, utilities and third party applications.
   template1 and template0 are
   meant as source databases to be copied by later CREATE
   DATABASE commands.  template0 should never
   be modified, but you can add objects to template1,
   which by default will be copied into databases created later.  See
   Section 22.3 for more details.
  
   Although initdb will attempt to create the
   specified data directory, it might not have permission if the parent
   directory of the desired data directory is root-owned. To initialize
   in such a setup, create an empty data directory as root, then use
   chown to assign ownership of that directory to the
   database user account, then su to become the
   database user to run initdb.
  
   initdb must be run as the user that will own the
   server process, because the server needs to have access to the
   files and directories that initdb creates.
   Since the server cannot be run as root, you must not run
   initdb as root either.  (It will in fact refuse
   to do so.)
  
    For security reasons the new cluster created by initdb
    will only be accessible by the cluster owner by default.  The
    --allow-group-access option allows any user in the same
    group as the cluster owner to read files in the cluster.  This is useful
    for performing backups as a non-privileged user.
  
   initdb initializes the database cluster's default locale
   and character set encoding. These can also be set separately for each
   database when it is created. initdb determines those
   settings for the template databases, which will serve as the default for
   all other databases.
  
   By default, initdb uses the locale provider
   libc (see Section 23.1.4). The
   libc locale provider takes the locale settings from the
   environment, and determines the encoding from the locale settings.
  
   To choose a different locale for the cluster, use the option
   --locale.  There are also individual options
   --lc-* and --icu-locale (see below) to
   set values for the individual locale categories.  Note that inconsistent
   settings for different locale categories can give nonsensical results, so
   this should be used with care.
  
   Alternatively, initdb can use the ICU library to provide
   locale services by specifying --locale-provider=icu. The
   server must be built with ICU support. To choose the specific ICU locale ID
   to apply, use the option --icu-locale.  Note that for
   implementation reasons and to support legacy code,
   initdb will still select and initialize libc locale
   settings when the ICU locale provider is used.
  
   When initdb runs, it will print out the locale settings
   it has chosen.  If you have complex requirements or specified multiple
   options, it is advisable to check that the result matches what was
   intended.
  
More details about locale settings can be found in Section 23.1.
   To alter the default encoding, use the --encoding.
   More details can be found in Section 23.3.
  
-A authmethod--auth=authmethod #
        This option specifies the default authentication method for local
        users used in pg_hba.conf (host
        and local lines).  See Section 20.1
        for an overview of valid values.
       
        initdb will
        prepopulate pg_hba.conf entries using the
        specified authentication method for non-replication as well as
        replication connections.
       
        Do not use trust unless you trust all local users on your
        system.  trust is the default for ease of installation.
       
--auth-host=authmethod #
        This option specifies the authentication method for local users via
        TCP/IP connections used in pg_hba.conf
        (host lines).
       
--auth-local=authmethod #
        This option specifies the authentication method for local users via
        Unix-domain socket connections used in pg_hba.conf
        (local lines).
       
-D directory--pgdata=directory #
        This option specifies the directory where the database cluster
        should be stored. This is the only information required by
        initdb, but you can avoid writing it by
        setting the PGDATA environment variable, which
        can be convenient since the database server
        (postgres) can find the data
        directory later by the same variable.
       
-E encoding--encoding=encoding #Selects the encoding of the template databases. This will also be the default encoding of any database you create later, unless you override it then. The character sets supported by the PostgreSQL server are described in Section 23.3.1.
        By default, the template database encoding is derived from the
        locale. If --no-locale is specified
        (or equivalently, if the locale is C or
        POSIX), then the default is UTF8
        for the ICU provider and SQL_ASCII for the
        libc provider.
       
-g--allow-group-access #
        Allows users in the same group as the cluster owner to read all cluster
        files created by initdb.  This option is ignored
        on Windows as it does not support
        POSIX-style group permissions.
       
--icu-locale=locale #Specifies the ICU locale when the ICU provider is used. Locale support is described in Section 23.1.
--icu-rules=rules #Specifies additional collation rules to customize the behavior of the default collation. This is supported for ICU only.
-k--data-checksums #
        Use checksums on data pages to help detect corruption by the
        I/O system that would otherwise be silent. Enabling checksums
        may incur a noticeable performance penalty. If set, checksums
        are calculated for all objects, in all databases. All checksum
        failures will be reported in the
        
        pg_stat_database view.
        See Section 28.2 for details.
       
--locale=locale #
        Sets the default locale for the database cluster.  If this
        option is not specified, the locale is inherited from the
        environment that initdb runs in. Locale
        support is described in Section 23.1.
       
        If --locale-provider is builtin,
        --locale or --builtin-locale must be
        specified and set to C or
        C.UTF-8.
       
--lc-collate=locale--lc-ctype=locale--lc-messages=locale--lc-monetary=locale--lc-numeric=locale--lc-time=locale #
        Like --locale, but only sets the locale in
        the specified category.
       
--no-locale #
        Equivalent to --locale=C.
       
--builtin-locale=locale #Specifies the locale name when the builtin provider is used. Locale support is described in Section 23.1.
--locale-provider={builtin|libc|icu} #
        This option sets the locale provider for databases created in the new
        cluster.  It can be overridden in the CREATE
        DATABASE command when new databases are subsequently
        created.  The default is libc (see Section 23.1.4).
       
--pwfile=filename #
        Makes initdb read the bootstrap superuser's password
        from a file.  The first line of the file is taken as the password.
       
-T config--text-search-config=config #Sets the default text search configuration. See default_text_search_config for further information.
-U username--username=username #
        Sets the user name of the
        bootstrap superuser.
        This defaults to the name of the operating-system user running
        initdb.
       
-W--pwprompt #
        Makes initdb prompt for a password
        to give the bootstrap superuser. If you don't plan on using password
        authentication, this is not important.  Otherwise you won't be
        able to use password authentication until you have a password
        set up.
       
-X directory--waldir=directory #This option specifies the directory where the write-ahead log should be stored.
--wal-segsize=size #Set the WAL segment size, in megabytes. This is the size of each individual file in the WAL log. The default size is 16 megabytes. The value must be a power of 2 between 1 and 1024 (megabytes). This option can only be set during initialization, and cannot be changed later.
It may be useful to adjust this size to control the granularity of WAL log shipping or archiving. Also, in databases with a high volume of WAL, the sheer number of WAL files per directory can become a performance and management problem. Increasing the WAL file size will reduce the number of WAL files.
Other, less commonly used, options are also available:
-c name=value--set name=value #
        Forcibly set the server parameter name
        to value during initdb,
        and also install that setting in the
        generated postgresql.conf file,
        so that it will apply during future server runs.
        This option can be given more than once to set several parameters.
        It is primarily useful when the environment is such that the server
        will not start at all using the default parameters.
       
-d--debug #
        Print debugging output from the bootstrap backend and a few other
        messages of lesser interest for the general public.
        The bootstrap backend is the program initdb
        uses to create the catalog tables.  This option generates a tremendous
        amount of extremely boring output.
       
--discard-caches #
        Run the bootstrap backend with the
        debug_discard_caches=1 option.
        This takes a very long time and is only of use for deep debugging.
       
-L directory #
        Specifies where initdb should find
        its input files to initialize the database cluster.  This is
        normally not necessary.  You will be told if you need to
        specify their location explicitly.
       
-n--no-clean #
        By default, when initdb
        determines that an error prevented it from completely creating the database
        cluster, it removes any files it might have created before discovering
        that it cannot finish the job. This option inhibits tidying-up and is
        thus useful for debugging.
       
-N--no-sync #
        By default, initdb will wait for all files to be
        written safely to disk.  This option causes initdb
        to return without waiting, which is faster, but means that a
        subsequent operating system crash can leave the data directory
        corrupt.  Generally, this option is useful for testing, but should not
        be used when creating a production installation.
       
--no-instructions #
        By default, initdb will write instructions for how
        to start the cluster at the end of its output. This option causes
        those instructions to be left out. This is primarily intended for use
        by tools that wrap initdb in platform-specific
        behavior, where those instructions are likely to be incorrect.
       
-s--show #Show internal settings and exit, without doing anything else. This can be used to debug the initdb installation.
--sync-method=method #
        When set to fsync, which is the default,
        initdb will recursively open and synchronize all
        files in the data directory.  The search for files will follow symbolic
        links for the WAL directory and each configured tablespace.
       
        On Linux, syncfs may be used instead to ask the
        operating system to synchronize the whole file systems that contain the
        data directory, the WAL files, and each tablespace.  See
        recovery_init_sync_method for information about
        the caveats to be aware of when using syncfs.
       
        This option has no effect when --no-sync is used.
       
-S--sync-only #
        Safely write all database files to disk and exit.  This does not
        perform any of the normal initdb operations.
        Generally, this option is useful for ensuring reliable recovery after
        changing fsync from off to
        on.
       
Other options:
PGDATA #
      Specifies the directory where the database cluster is to be
      stored; can be overridden using the -D option.
     
PG_COLOR #
      Specifies whether to use color in diagnostic messages. Possible values
      are always, auto and
      never.
     
TZ #Specifies the default time zone of the created database cluster. The value should be a full time zone name (see Section 8.5.3).
   initdb can also be invoked via
   pg_ctl initdb.