<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>pg_basebackup</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.1.15 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="PostgreSQL Client Applications"
HREF="reference-client.html"><LINK
REL="PREVIOUS"
TITLE="ecpg"
HREF="app-ecpg.html"><LINK
REL="NEXT"
TITLE="pg_config"
HREF="app-pgconfig.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2015-02-07T09:47:53"></HEAD
><BODY
CLASS="REFENTRY"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.1.15 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="ecpg"
HREF="app-ecpg.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="reference-client.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="pg_config"
HREF="app-pgconfig.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="APP-PGBASEBACKUP"
></A
>pg_basebackup</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN78453"
></A
><H2
>Name</H2
>pg_basebackup -- take a base backup of a <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> cluster</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN78459"
></A
><H2
>Synopsis</H2
><P
><TT
CLASS="COMMAND"
>pg_basebackup</TT
> [<TT
CLASS="REPLACEABLE"
><I
>option</I
></TT
>...]</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN78464"
></A
><H2
> Description
</H2
><P
> <SPAN
CLASS="APPLICATION"
>pg_basebackup</SPAN
> is used to take base backups of
a running <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> database cluster. These
are taken without affecting other clients to the database, and can be used
both for point-in-time recovery (see <A
HREF="continuous-archiving.html"
>Section 24.3</A
>)
and as the starting point for a log shipping or streaming replication standby
servers (see <A
HREF="warm-standby.html"
>Section 25.2</A
>).
</P
><P
> <SPAN
CLASS="APPLICATION"
>pg_basebackup</SPAN
> makes a binary copy of the database
cluster files, while making sure the system is put in and
out of backup mode automatically. Backups are always taken of the entire
database cluster; it is not possible to back up individual databases or
database objects. For individual database backups, a tool such as
<A
HREF="app-pgdump.html"
>pg_dump</A
> must be used.
</P
><P
> The backup is made over a regular <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
connection, and uses the replication protocol. The connection must be
made with a user having <TT
CLASS="LITERAL"
>REPLICATION</TT
> permissions (see
<A
HREF="role-attributes.html"
>Section 20.2</A
>), and the user must be granted explicit
permissions in <TT
CLASS="FILENAME"
>pg_hba.conf</TT
>. The server must also
be configured with <A
HREF="runtime-config-replication.html#GUC-MAX-WAL-SENDERS"
>max_wal_senders</A
> set high enough
to leave at least one session available for the backup.
</P
><P
> There can be multiple <TT
CLASS="COMMAND"
>pg_basebackup</TT
>s running at the same time, but it is
better from a performance point of view to take only one backup, and copy
the result.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN78482"
></A
><H2
>Options</H2
><P
> The following command-line options control the location and format of the
output.
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="OPTION"
>-D <TT
CLASS="REPLACEABLE"
><I
>directory</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--pgdata=<TT
CLASS="REPLACEABLE"
><I
>directory</I
></TT
></TT
></DT
><DD
><P
> Directory to write the output to.
</P
><P
> When the backup is in tar mode, and the directory is specified as
<TT
CLASS="LITERAL"
>-</TT
> (dash), the tar file will be written to
<TT
CLASS="LITERAL"
>stdout</TT
>.
</P
><P
> This parameter is required.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-F <TT
CLASS="REPLACEABLE"
><I
>format</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--format=<TT
CLASS="REPLACEABLE"
><I
>format</I
></TT
></TT
></DT
><DD
><P
> Selects the format for the output. <TT
CLASS="REPLACEABLE"
><I
>format</I
></TT
>
can be one of the following:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>p</TT
><BR><TT
CLASS="LITERAL"
>plain</TT
></DT
><DD
><P
> Write the output as plain files, with the same layout as the
current data directory and tablespaces. When the cluster has
no additional tablespaces, the whole database will be placed in
the target directory. If the cluster contains additional
tablespaces, the main data directory will be placed in the
target directory, but all other tablespaces will be placed
in the same absolute path as they have on the server.
</P
><P
> This is the default format.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>t</TT
><BR><TT
CLASS="LITERAL"
>tar</TT
></DT
><DD
><P
> Write the output as tar files in the target directory. The main
data directory will be written to a file named
<TT
CLASS="FILENAME"
>base.tar</TT
>, and all other tablespaces will
be named after the tablespace OID.
</P
><P
> If the value <TT
CLASS="LITERAL"
>-</TT
> (dash) is specified as
target directory, the tar contents will be written to
standard output, suitable for piping to for example
<SPAN
CLASS="PRODUCTNAME"
>gzip</SPAN
>. This is only possible if
the cluster has no additional tablespaces.
</P
></DD
></DL
></DIV
><P></P
></DD
><DT
><TT
CLASS="OPTION"
>-x</TT
><BR><TT
CLASS="OPTION"
>--xlog</TT
></DT
><DD
><P
> Includes the required transaction log files (WAL files) in the
backup. This will include all transaction logs generated during
the backup. If this option is specified, it is possible to start
a postmaster directly in the extracted directory without the need
to consult the log archive, thus making this a completely standalone
backup.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> The transaction log files are collected at the end of the backup.
Therefore, it is necessary for the
<A
HREF="runtime-config-replication.html#GUC-WAL-KEEP-SEGMENTS"
>wal_keep_segments</A
> parameter to be set high
enough that the log is not removed before the end of the backup.
If the log has been rotated when it's time to transfer it, the
backup will fail and be unusable.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="OPTION"
>-z</TT
><BR><TT
CLASS="OPTION"
>--gzip</TT
></DT
><DD
><P
> Enables gzip compression of tar file output, with the default
compression level. Compression is only available when using
the tar format.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-Z <TT
CLASS="REPLACEABLE"
><I
>level</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--compress=<TT
CLASS="REPLACEABLE"
><I
>level</I
></TT
></TT
></DT
><DD
><P
> Enables gzip compression of tar file output, and specifies the
compression level (1 through 9, 9 being best
compression). Compression is only available when using the tar
format.
</P
></DD
></DL
></DIV
><P>
</P
><P
> The following command-line options control the generation of the
backup and the running of the program.
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="OPTION"
>-c <TT
CLASS="REPLACEABLE"
><I
>fast|spread</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--checkpoint=<TT
CLASS="REPLACEABLE"
><I
>fast|spread</I
></TT
></TT
></DT
><DD
><P
> Sets checkpoint mode to fast or spread (default).
</P
></DD
><DT
><TT
CLASS="OPTION"
>-l <TT
CLASS="REPLACEABLE"
><I
>label</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--label=<TT
CLASS="REPLACEABLE"
><I
>label</I
></TT
></TT
></DT
><DD
><P
> Sets the label for the backup. If none is specified, a default value of
<TT
CLASS="LITERAL"
>pg_basebackup base backup</TT
> will be used.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-P</TT
><BR><TT
CLASS="OPTION"
>--progress</TT
></DT
><DD
><P
> Enables progress reporting. Turning this on will deliver an approximate
progress report during the backup. Since the database may change during
the backup, this is only an approximation and may not end at exactly
<TT
CLASS="LITERAL"
>100%</TT
>. In particular, when WAL log is included in the
backup, the total amount of data cannot be estimated in advance, and
in this case the estimated target size will increase once it passes the
total estimate without WAL.
</P
><P
> When this is enabled, the backup will start by enumerating the size of
the entire database, and then go back and send the actual contents.
This may make the backup take slightly longer, and in particular it
will take longer before the first data is sent.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-v</TT
><BR><TT
CLASS="OPTION"
>--verbose</TT
></DT
><DD
><P
> Enables verbose mode. Will output some extra steps during startup and
shutdown, as well as show the exact file name that is currently being
processed if progress reporting is also enabled.
</P
></DD
></DL
></DIV
><P>
</P
><P
> The following command-line options control the database connection parameters.
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="OPTION"
>-h <TT
CLASS="REPLACEABLE"
><I
>host</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--host=<TT
CLASS="REPLACEABLE"
><I
>host</I
></TT
></TT
></DT
><DD
><P
> Specifies the host name of the machine on which the server is
running. If the value begins with a slash, it is used as the
directory for the Unix domain socket. The default is taken
from the <TT
CLASS="ENVAR"
>PGHOST</TT
> environment variable, if set,
else a Unix domain socket connection is attempted.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-p <TT
CLASS="REPLACEABLE"
><I
>port</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--port=<TT
CLASS="REPLACEABLE"
><I
>port</I
></TT
></TT
></DT
><DD
><P
> Specifies the TCP port or local Unix domain socket file
extension on which the server is listening for connections.
Defaults to the <TT
CLASS="ENVAR"
>PGPORT</TT
> environment variable, if
set, or a compiled-in default.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-U <TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--username=<TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
></TT
></DT
><DD
><P
> User name to connect as.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-w</TT
><BR><TT
CLASS="OPTION"
>--no-password</TT
></DT
><DD
><P
> Never issue a password prompt. If the server requires
password authentication and a password is not available by
other means such as a <TT
CLASS="FILENAME"
>.pgpass</TT
> file, the
connection attempt will fail. This option can be useful in
batch jobs and scripts where no user is present to enter a
password.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-W</TT
><BR><TT
CLASS="OPTION"
>--password</TT
></DT
><DD
><P
> Force <SPAN
CLASS="APPLICATION"
>pg_basebackup</SPAN
> to prompt for a
password before connecting to a database.
</P
><P
> This option is never essential, since
<SPAN
CLASS="APPLICATION"
>pg_basebackup</SPAN
> will automatically prompt
for a password if the server demands password authentication.
However, <SPAN
CLASS="APPLICATION"
>pg_basebackup</SPAN
> will waste a
connection attempt finding out that the server wants a password.
In some cases it is worth typing <TT
CLASS="OPTION"
>-W</TT
> to avoid the extra
connection attempt.
</P
></DD
></DL
></DIV
><P>
</P
><P
> Other, less commonly used, parameters are also available:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="OPTION"
>-V</TT
><BR><TT
CLASS="OPTION"
>--version</TT
></DT
><DD
><P
> Print the <SPAN
CLASS="APPLICATION"
>pg_basebackup</SPAN
> version and exit.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-?</TT
><BR><TT
CLASS="OPTION"
>--help</TT
></DT
><DD
><P
> Show help about <SPAN
CLASS="APPLICATION"
>pg_basebackup</SPAN
> command line
arguments, and exit.
</P
></DD
></DL
></DIV
><P>
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN78661"
></A
><H2
>Environment</H2
><P
> This utility, like most other <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> utilities,
uses the environment variables supported by <SPAN
CLASS="APPLICATION"
>libpq</SPAN
>
(see <A
HREF="libpq-envars.html"
>Section 31.13</A
>).
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN78667"
></A
><H2
>Notes</H2
><P
> The backup will include all files in the data directory and tablespaces,
including the configuration files and any additional files placed in the
directory by third parties. Only regular files and directories are allowed
in the data directory, no symbolic links or special device files.
</P
><P
> The way <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> manages tablespaces, the path
for all additional tablespaces must be identical whenever a backup is
restored. The main data directory, however, is relocatable to any location.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN78672"
></A
><H2
>Examples</H2
><P
> To create a base backup of the server at <TT
CLASS="LITERAL"
>mydbserver</TT
>
and store it in the local directory
<TT
CLASS="FILENAME"
>/usr/local/pgsql/data</TT
>:
</P><PRE
CLASS="SCREEN"
><SAMP
CLASS="PROMPT"
>$</SAMP
> <KBD
CLASS="USERINPUT"
>pg_basebackup -h mydbserver -D /usr/local/pgsql/data</KBD
></PRE
><P>
</P
><P
> To create a backup of the local server with one compressed
tar file for each tablespace, and store it in the directory
<TT
CLASS="FILENAME"
>backup</TT
>, showing a progress report while running:
</P><PRE
CLASS="SCREEN"
><SAMP
CLASS="PROMPT"
>$</SAMP
> <KBD
CLASS="USERINPUT"
>pg_basebackup -D backup -Ft -z -P</KBD
></PRE
><P>
</P
><P
> To create a backup of a single-tablespace local database and compress
this with <SPAN
CLASS="PRODUCTNAME"
>bzip2</SPAN
>:
</P><PRE
CLASS="SCREEN"
><SAMP
CLASS="PROMPT"
>$</SAMP
> <KBD
CLASS="USERINPUT"
>pg_basebackup -D - -Ft | bzip2 > backup.tar.bz2</KBD
></PRE
><P>
(This command will fail if there are multiple tablespaces in the
database.)
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN78690"
></A
><H2
>See Also</H2
><A
HREF="app-pgdump.html"
>pg_dump</A
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="app-ecpg.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="app-pgconfig.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><SPAN
CLASS="APPLICATION"
>ecpg</SPAN
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="reference-client.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>pg_config</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
