diff options
Diffstat (limited to 'doc/src/sgml/html/app-pgchecksums.html')
| -rw-r--r-- | doc/src/sgml/html/app-pgchecksums.html | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/doc/src/sgml/html/app-pgchecksums.html b/doc/src/sgml/html/app-pgchecksums.html new file mode 100644 index 0000000..3e08a4d --- /dev/null +++ b/doc/src/sgml/html/app-pgchecksums.html @@ -0,0 +1,75 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>pg_checksums</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="pgarchivecleanup.html" title="pg_archivecleanup" /><link rel="next" href="app-pgcontroldata.html" title="pg_controldata" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center"><span class="application">pg_checksums</span></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="pgarchivecleanup.html" title="pg_archivecleanup">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="reference-server.html" title="PostgreSQL Server Applications">Up</a></td><th width="60%" align="center">PostgreSQL Server Applications</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 15.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="app-pgcontroldata.html" title="pg_controldata">Next</a></td></tr></table><hr /></div><div class="refentry" id="APP-PGCHECKSUMS"><div class="titlepage"></div><a id="id-1.9.5.5.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle"><span class="application">pg_checksums</span></span></h2><p>pg_checksums — enable, disable or check data checksums in a <span class="productname">PostgreSQL</span> database cluster</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p id="id-1.9.5.5.4.1"><code class="command">pg_checksums</code> [<em class="replaceable"><code>option</code></em>...] [[ <code class="option">-D</code> | <code class="option">--pgdata</code> ]<em class="replaceable"><code>datadir</code></em>]</p></div></div><div class="refsect1" id="R1-APP-PG_CHECKSUMS-1"><h2>Description</h2><p> + <span class="application">pg_checksums</span> checks, enables or disables data + checksums in a <span class="productname">PostgreSQL</span> cluster. The server + must be shut down cleanly before running + <span class="application">pg_checksums</span>. When verifying checksums, the exit + status is zero if there are no checksum errors, and nonzero if at least one + checksum failure is detected. When enabling or disabling checksums, the + exit status is nonzero if the operation failed. + </p><p> + When verifying checksums, every file in the cluster is scanned. When + enabling checksums, each relation file block with a changed checksum is + rewritten in-place. + Disabling checksums only updates the file <code class="filename">pg_control</code>. + </p></div><div class="refsect1" id="id-1.9.5.5.6"><h2>Options</h2><p> + The following command-line options are available: + + </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">-D <em class="replaceable"><code>directory</code></em></code><br /></span><span class="term"><code class="option">--pgdata=<em class="replaceable"><code>directory</code></em></code></span></dt><dd><p> + Specifies the directory where the database cluster is stored. + </p></dd><dt><span class="term"><code class="option">-c</code><br /></span><span class="term"><code class="option">--check</code></span></dt><dd><p> + Checks checksums. This is the default mode if nothing else is + specified. + </p></dd><dt><span class="term"><code class="option">-d</code><br /></span><span class="term"><code class="option">--disable</code></span></dt><dd><p> + Disables checksums. + </p></dd><dt><span class="term"><code class="option">-e</code><br /></span><span class="term"><code class="option">--enable</code></span></dt><dd><p> + Enables checksums. + </p></dd><dt><span class="term"><code class="option">-f <em class="replaceable"><code>filenode</code></em></code><br /></span><span class="term"><code class="option">--filenode=<em class="replaceable"><code>filenode</code></em></code></span></dt><dd><p> + Only validate checksums in the relation with filenode + <em class="replaceable"><code>filenode</code></em>. + </p></dd><dt><span class="term"><code class="option">-N</code><br /></span><span class="term"><code class="option">--no-sync</code></span></dt><dd><p> + By default, <code class="command">pg_checksums</code> will wait for all files + to be written safely to disk. This option causes + <code class="command">pg_checksums</code> to return without waiting, which is + faster, but means that a subsequent operating system crash can leave + the updated data directory corrupt. Generally, this option is useful + for testing but should not be used on a production installation. + This option has no effect when using <code class="literal">--check</code>. + </p></dd><dt><span class="term"><code class="option">-P</code><br /></span><span class="term"><code class="option">--progress</code></span></dt><dd><p> + Enable progress reporting. Turning this on will deliver a progress + report while checking or enabling checksums. + </p></dd><dt><span class="term"><code class="option">-v</code><br /></span><span class="term"><code class="option">--verbose</code></span></dt><dd><p> + Enable verbose output. Lists all checked files. + </p></dd><dt><span class="term"><code class="option">-V</code><br /></span><span class="term"><code class="option">--version</code></span></dt><dd><p> + Print the <span class="application">pg_checksums</span> version and exit. + </p></dd><dt><span class="term"><code class="option">-?</code><br /></span><span class="term"><code class="option">--help</code></span></dt><dd><p> + Show help about <span class="application">pg_checksums</span> command line + arguments, and exit. + </p></dd></dl></div><p> + </p></div><div class="refsect1" id="id-1.9.5.5.7"><h2>Environment</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="envar">PGDATA</code></span></dt><dd><p> + Specifies the directory where the database cluster is + stored; can be overridden using the <code class="option">-D</code> option. + </p></dd><dt><span class="term"><code class="envar">PG_COLOR</code></span></dt><dd><p> + Specifies whether to use color in diagnostic messages. Possible values + are <code class="literal">always</code>, <code class="literal">auto</code> and + <code class="literal">never</code>. + </p></dd></dl></div></div><div class="refsect1" id="id-1.9.5.5.8"><h2>Notes</h2><p> + Enabling checksums in a large cluster can potentially take a long time. + During this operation, the cluster or other programs that write to the + data directory must not be started or else data loss may occur. + </p><p> + When using a replication setup with tools which perform direct copies + of relation file blocks (for example <a class="xref" href="app-pgrewind.html" title="pg_rewind"><span class="refentrytitle"><span class="application">pg_rewind</span></span></a>), + enabling or disabling checksums can lead to page corruptions in the + shape of incorrect checksums if the operation is not done consistently + across all nodes. When enabling or disabling checksums in a replication + setup, it is thus recommended to stop all the clusters before switching + them all consistently. Destroying all standbys, performing the operation + on the primary and finally recreating the standbys from scratch is also + safe. + </p><p> + If <span class="application">pg_checksums</span> is aborted or killed while + enabling or disabling checksums, the cluster's data checksum configuration + remains unchanged, and <span class="application">pg_checksums</span> can be + re-run to perform the same operation. + </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="pgarchivecleanup.html" title="pg_archivecleanup">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="reference-server.html" title="PostgreSQL Server Applications">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="app-pgcontroldata.html" title="pg_controldata">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="application">pg_archivecleanup</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 15.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> <span class="application">pg_controldata</span></td></tr></table></div></body></html>
\ No newline at end of file |