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| <!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 a |
| <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> |
| <span class="application">pg_verifybackup</span> is used to check the |
| integrity of a database cluster backup taken using |
| <code class="command">pg_basebackup</code> against a |
| <code class="literal">backup_manifest</code> generated by the server at the time |
| of the backup. The backup must be stored in the "plain" |
| format; a "tar" format backup can be checked after extracting it. |
| </p><p> |
| It is important to note that the validation which is performed by |
| <span class="application">pg_verifybackup</span> does not and cannot include |
| every check which will be performed by a running server when attempting |
| to make use of the backup. Even if you use this tool, you should still |
| perform test restores and verify that the resulting databases work as |
| expected and that they appear to contain the correct data. However, |
| <span class="application">pg_verifybackup</span> can detect many problems |
| that commonly occur due to storage problems or user error. |
| </p><p> |
| Backup verification proceeds in four stages. First, |
| <code class="literal">pg_verifybackup</code> reads the |
| <code class="literal">backup_manifest</code> file. If that file |
| does not exist, cannot be read, is malformed, or fails verification |
| against its own internal checksum, <code class="literal">pg_verifybackup</code> |
| will terminate with a fatal error. |
| </p><p> |
| Second, <code class="literal">pg_verifybackup</code> will attempt to verify that |
| the data files currently stored on disk are exactly the same as the data |
| files which the server intended to send, with some exceptions that are |
| described below. Extra and missing files will be detected, with a few |
| exceptions. This step will ignore the presence or absence of, or any |
| modifications to, <code class="literal">postgresql.auto.conf</code>, |
| <code class="literal">standby.signal</code>, and <code class="literal">recovery.signal</code>, |
| because it is expected that these files may have been created or modified |
| as part of the process of taking the backup. It also won't complain about |
| a <code class="literal">backup_manifest</code> file in the target directory or |
| about anything inside <code class="literal">pg_wal</code>, even though these |
| files won't be listed in the backup manifest. Only files are checked; |
| the presence or absence of directories is not verified, except |
| indirectly: if a directory is missing, any files it should have contained |
| will necessarily also be missing. |
| </p><p> |
| Next, <code class="literal">pg_verifybackup</code> will checksum all the files, |
| compare the checksums against the values in the manifest, and emit errors |
| for any files for which the computed checksum does not match the |
| checksum stored in the manifest. This step is not performed for any files |
| which produced errors in the previous step, since they are already known |
| to have problems. Files which were ignored in the previous step are also |
| ignored in this step. |
| </p><p> |
| Finally, <code class="literal">pg_verifybackup</code> will use the manifest to |
| verify that the write-ahead log records which will be needed to recover |
| the backup are present and that they can be read and parsed. The |
| <code class="literal">backup_manifest</code> contains information about which |
| write-ahead log records will be needed, and |
| <code class="literal">pg_verifybackup</code> will use that information to |
| invoke <code class="literal">pg_waldump</code> to parse those write-ahead log |
| records. The <code class="literal">--quiet</code> flag will be used, so that |
| <code class="literal">pg_waldump</code> will only report errors, without producing |
| any other output. While this level of verification is sufficient to |
| detect obvious problems such as a missing file or one whose internal |
| checksums do not match, they aren't extensive enough to detect every |
| possible problem that might occur when attempting to recover. For |
| instance, a server bug that produces write-ahead log records that have |
| the correct checksums but specify nonsensical actions can't be detected |
| by this method. |
| </p><p> |
| Note that if extra WAL files which are not required to recover the backup |
| are present, they will not be checked by this tool, although |
| a separate invocation of <code class="literal">pg_waldump</code> could be used for |
| that purpose. Also note that WAL verification is version-specific: you |
| must use the version of <code class="literal">pg_verifybackup</code>, and thus of |
| <code class="literal">pg_waldump</code>, which pertains to the backup being checked. |
| In contrast, the data file integrity checks should work with any version |
| of the server that generates a <code class="literal">backup_manifest</code> file. |
| </p></div><div class="refsect1" id="id-1.9.4.19.6"><h2>Options</h2><p> |
| <span class="application">pg_verifybackup</span> accepts the following |
| command-line arguments: |
|
|
| </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> |
| Exit as soon as a problem with the backup is detected. If this option |
| is not specified, <code class="literal">pg_verifybackup</code> will continue |
| checking the backup even after a problem has been detected, and will |
| report all problems detected as errors. |
| </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> |
| Ignore the specified file or directory, which should be expressed |
| as a relative path name, when comparing the list of data files |
| actually present in the backup to those listed in the |
| <code class="literal">backup_manifest</code> file. If a directory is |
| specified, this option affects the entire subtree rooted at that |
| location. Complaints about extra files, missing files, file size |
| differences, or checksum mismatches will be suppressed if the |
| relative path name matches the specified path name. This option |
| can be specified multiple times. |
| </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> |
| Use the manifest file at the specified path, rather than one located |
| in the root of the backup directory. |
| </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> |
| Don't attempt to parse write-ahead log data that will be needed |
| to recover from this backup. |
| </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 verifying checksums. |
| </p><p> |
| This option cannot be used together with the option |
| <code class="option">--quiet</code>. |
| </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> |
| Don't print anything when a backup is successfully verified. |
| </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> |
| Do not verify data file checksums. The presence or absence of |
| files and the sizes of those files will still be checked. This is |
| much faster, because the files themselves do not need to be read. |
| </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> |
| Try to parse WAL files stored in the specified directory, rather than |
| in <code class="literal">pg_wal</code>. This may be useful if the backup is |
| stored in a separate location from the WAL archive. |
| </p></dd></dl></div><p> |
| </p><p> |
| Other options are also available: |
|
|
| </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> |
| Print the <span class="application">pg_verifybackup</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_verifybackup</span> command |
| line arguments, and exit. |
| </p></dd></dl></div><p> |
| </p></div><div class="refsect1" id="id-1.9.4.19.7"><h2>Examples</h2><p> |
| To create a base backup of the server at <code class="literal">mydbserver</code> and |
| verify the integrity of the backup: |
| </p><pre class="screen"> |
| <code class="prompt">$</code> <strong class="userinput"><code>pg_basebackup -h mydbserver -D /usr/local/pgsql/data</code></strong> |
| <code class="prompt">$</code> <strong class="userinput"><code>pg_verifybackup /usr/local/pgsql/data</code></strong> |
| </pre><p> |
| </p><p> |
| To create a base backup of the server at <code class="literal">mydbserver</code>, move |
| the manifest somewhere outside the backup directory, and verify the |
| backup: |
| </p><pre class="screen"> |
| <code class="prompt">$</code> <strong class="userinput"><code>pg_basebackup -h mydbserver -D /usr/local/pgsql/backup1234</code></strong> |
| <code class="prompt">$</code> <strong class="userinput"><code>mv /usr/local/pgsql/backup1234/backup_manifest /my/secure/location/backup_manifest.1234</code></strong> |
| <code class="prompt">$</code> <strong class="userinput"><code>pg_verifybackup -m /my/secure/location/backup_manifest.1234 /usr/local/pgsql/backup1234</code></strong> |
| </pre><p> |
| </p><p> |
| To verify a backup while ignoring a file that was added manually to the |
| backup directory, and also skipping checksum verification: |
| </p><pre class="screen"> |
| <code class="prompt">$</code> <strong class="userinput"><code>pg_basebackup -h mydbserver -D /usr/local/pgsql/data</code></strong> |
| <code class="prompt">$</code> <strong class="userinput"><code>edit /usr/local/pgsql/data/note.to.self</code></strong> |
| <code class="prompt">$</code> <strong class="userinput"><code>pg_verifybackup --ignore=note.to.self --skip-checksums /usr/local/pgsql/data</code></strong> |
| </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> |
