codekingpro/portable-devtools

1<?xml version="1.0" encoding="UTF-8" standalone="no"?>2<!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_verifybackup</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="app-pgrestore.html" title="pg_restore" /><link rel="next" href="app-psql.html" title="psql" /></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_verifybackup</span></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="app-pgrestore.html" title="pg_restore">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="reference-client.html" title="PostgreSQL Client Applications">Up</a></td><th width="60%" align="center">PostgreSQL Client Applications</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="app-psql.html" title="psql">Next</a></td></tr></table><hr /></div><div class="refentry" id="APP-PGVERIFYBACKUP"><div class="titlepage"></div><a id="id-1.9.4.19.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle"><span class="application">pg_verifybackup</span></span></h2><p>pg_verifybackup — verify the integrity of a base backup of a3  <span class="productname">PostgreSQL</span> cluster</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p id="id-1.9.4.19.4.1"><code class="command">pg_verifybackup</code> [<em class="replaceable"><code>option</code></em>...]</p></div></div><div class="refsect1" id="id-1.9.4.19.5"><h2>Description</h2><p>4   <span class="application">pg_verifybackup</span> is used to check the5   integrity of a database cluster backup taken using6   <code class="command">pg_basebackup</code> against a7   <code class="literal">backup_manifest</code> generated by the server at the time8   of the backup.  The backup must be stored in the "plain"9   format; a "tar" format backup can be checked after extracting it.10  </p><p>11   It is important to note that the validation which is performed by12   <span class="application">pg_verifybackup</span> does not and cannot include13   every check which will be performed by a running server when attempting14   to make use of the backup. Even if you use this tool, you should still15   perform test restores and verify that the resulting databases work as16   expected and that they appear to contain the correct data. However,17   <span class="application">pg_verifybackup</span> can detect many problems18   that commonly occur due to storage problems or user error.19  </p><p>20   Backup verification proceeds in four stages. First,21   <code class="literal">pg_verifybackup</code> reads the22   <code class="literal">backup_manifest</code> file. If that file23   does not exist, cannot be read, is malformed, or fails verification24   against its own internal checksum, <code class="literal">pg_verifybackup</code>25   will terminate with a fatal error.26  </p><p>27   Second, <code class="literal">pg_verifybackup</code> will attempt to verify that28   the data files currently stored on disk are exactly the same as the data29   files which the server intended to send, with some exceptions that are30   described below. Extra and missing files will be detected, with a few31   exceptions.  This step will ignore the presence or absence of, or any32   modifications to, <code class="literal">postgresql.auto.conf</code>,33   <code class="literal">standby.signal</code>, and <code class="literal">recovery.signal</code>,34   because it is expected that these files may have been created or modified35   as part of the process of taking the backup. It also won't complain about36   a <code class="literal">backup_manifest</code> file in the target directory or37   about anything inside <code class="literal">pg_wal</code>, even though these38   files won't be listed in the backup manifest. Only files are checked;39   the presence or absence of directories is not verified, except40   indirectly: if a directory is missing, any files it should have contained41   will necessarily also be missing.42  </p><p>43   Next, <code class="literal">pg_verifybackup</code> will checksum all the files,44   compare the checksums against the values in the manifest, and emit errors45   for any files for which the computed checksum does not match the46   checksum stored in the manifest. This step is not performed for any files47   which produced errors in the previous step, since they are already known48   to have problems. Files which were ignored in the previous step are also49   ignored in this step.50  </p><p>51   Finally, <code class="literal">pg_verifybackup</code> will use the manifest to52   verify that the write-ahead log records which will be needed to recover53   the backup are present and that they can be read and parsed. The54   <code class="literal">backup_manifest</code> contains information about which55   write-ahead log records will be needed, and56   <code class="literal">pg_verifybackup</code> will use that information to57   invoke <code class="literal">pg_waldump</code> to parse those write-ahead log58   records. The <code class="literal">--quiet</code> flag will be used, so that59   <code class="literal">pg_waldump</code> will only report errors, without producing60   any other output. While this level of verification is sufficient to61   detect obvious problems such as a missing file or one whose internal62   checksums do not match, they aren't extensive enough to detect every63   possible problem that might occur when attempting to recover. For64   instance, a server bug that produces write-ahead log records that have65   the correct checksums but specify nonsensical actions can't be detected66   by this method.67  </p><p>68   Note that if extra WAL files which are not required to recover the backup69   are present, they will not be checked by this tool, although70   a separate invocation of <code class="literal">pg_waldump</code> could be used for71   that purpose. Also note that WAL verification is version-specific: you72   must use the version of <code class="literal">pg_verifybackup</code>, and thus of73   <code class="literal">pg_waldump</code>, which pertains to the backup being checked.74   In contrast, the data file integrity checks should work with any version75   of the server that generates a <code class="literal">backup_manifest</code> file.76  </p></div><div class="refsect1" id="id-1.9.4.19.6"><h2>Options</h2><p>77    <span class="application">pg_verifybackup</span> accepts the following78    command-line arguments:79 80    </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">-e</code><br /></span><span class="term"><code class="option">--exit-on-error</code></span></dt><dd><p>81        Exit as soon as a problem with the backup is detected. If this option82        is not specified, <code class="literal">pg_verifybackup</code> will continue83        checking the backup even after a problem has been detected, and will84        report all problems detected as errors.85       </p></dd><dt><span class="term"><code class="option">-i <em class="replaceable"><code>path</code></em></code><br /></span><span class="term"><code class="option">--ignore=<em class="replaceable"><code>path</code></em></code></span></dt><dd><p>86        Ignore the specified file or directory, which should be expressed87        as a relative path name, when comparing the list of data files88        actually present in the backup to those listed in the89        <code class="literal">backup_manifest</code> file.  If a directory is90        specified, this option affects the entire subtree rooted at that91        location. Complaints about extra files, missing files, file size92        differences, or checksum mismatches will be suppressed if the93        relative path name matches the specified path name. This option94        can be specified multiple times.95       </p></dd><dt><span class="term"><code class="option">-m <em class="replaceable"><code>path</code></em></code><br /></span><span class="term"><code class="option">--manifest-path=<em class="replaceable"><code>path</code></em></code></span></dt><dd><p>96        Use the manifest file at the specified path, rather than one located97        in the root of the backup directory.98       </p></dd><dt><span class="term"><code class="option">-n</code><br /></span><span class="term"><code class="option">--no-parse-wal</code></span></dt><dd><p>99        Don't attempt to parse write-ahead log data that will be needed100        to recover from this backup.101       </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>102        Enable progress reporting. Turning this on will deliver a progress103        report while verifying checksums.104       </p><p>105        This option cannot be used together with the option106        <code class="option">--quiet</code>.107       </p></dd><dt><span class="term"><code class="option">-q</code><br /></span><span class="term"><code class="option">--quiet</code></span></dt><dd><p>108        Don't print anything when a backup is successfully verified.109       </p></dd><dt><span class="term"><code class="option">-s</code><br /></span><span class="term"><code class="option">--skip-checksums</code></span></dt><dd><p>110        Do not verify data file checksums. The presence or absence of111        files and the sizes of those files will still be checked. This is112        much faster, because the files themselves do not need to be read.113       </p></dd><dt><span class="term"><code class="option">-w <em class="replaceable"><code>path</code></em></code><br /></span><span class="term"><code class="option">--wal-directory=<em class="replaceable"><code>path</code></em></code></span></dt><dd><p>114        Try to parse WAL files stored in the specified directory, rather than115        in <code class="literal">pg_wal</code>. This may be useful if the backup is116        stored in a separate location from the WAL archive.117       </p></dd></dl></div><p>118   </p><p>119    Other options are also available:120 121    </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">-V</code><br /></span><span class="term"><code class="option">--version</code></span></dt><dd><p>122       Print the <span class="application">pg_verifybackup</span> version and exit.123       </p></dd><dt><span class="term"><code class="option">-?</code><br /></span><span class="term"><code class="option">--help</code></span></dt><dd><p>124       Show help about <span class="application">pg_verifybackup</span> command125       line arguments, and exit.126       </p></dd></dl></div><p>127   </p></div><div class="refsect1" id="id-1.9.4.19.7"><h2>Examples</h2><p>128   To create a base backup of the server at <code class="literal">mydbserver</code> and129   verify the integrity of the backup:130</p><pre class="screen">131<code class="prompt">$</code> <strong class="userinput"><code>pg_basebackup -h mydbserver -D /usr/local/pgsql/data</code></strong>132<code class="prompt">$</code> <strong class="userinput"><code>pg_verifybackup /usr/local/pgsql/data</code></strong>133</pre><p>134  </p><p>135   To create a base backup of the server at <code class="literal">mydbserver</code>, move136   the manifest somewhere outside the backup directory, and verify the137   backup:138</p><pre class="screen">139<code class="prompt">$</code> <strong class="userinput"><code>pg_basebackup -h mydbserver -D /usr/local/pgsql/backup1234</code></strong>140<code class="prompt">$</code> <strong class="userinput"><code>mv /usr/local/pgsql/backup1234/backup_manifest /my/secure/location/backup_manifest.1234</code></strong>141<code class="prompt">$</code> <strong class="userinput"><code>pg_verifybackup -m /my/secure/location/backup_manifest.1234 /usr/local/pgsql/backup1234</code></strong>142</pre><p>143  </p><p>144   To verify a backup while ignoring a file that was added manually to the145   backup directory, and also skipping checksum verification:146</p><pre class="screen">147<code class="prompt">$</code> <strong class="userinput"><code>pg_basebackup -h mydbserver -D /usr/local/pgsql/data</code></strong>148<code class="prompt">$</code> <strong class="userinput"><code>edit /usr/local/pgsql/data/note.to.self</code></strong>149<code class="prompt">$</code> <strong class="userinput"><code>pg_verifybackup --ignore=note.to.self --skip-checksums /usr/local/pgsql/data</code></strong>150</pre></div><div class="refsect1" id="id-1.9.4.19.8"><h2>See Also</h2><span class="simplelist"><a class="xref" href="app-pgbasebackup.html" title="pg_basebackup"><span class="refentrytitle"><span class="application">pg_basebackup</span></span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="app-pgrestore.html" title="pg_restore">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="reference-client.html" title="PostgreSQL Client Applications">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="app-psql.html" title="psql">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="application">pg_restore</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> <span class="application">psql</span></td></tr></table></div></body></html>