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diff --git a/doc/src/sgml/html/pgupgrade.html b/doc/src/sgml/html/pgupgrade.html new file mode 100644 index 0000000..6920586 --- /dev/null +++ b/doc/src/sgml/html/pgupgrade.html @@ -0,0 +1,432 @@ +<?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_upgrade</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="pgtesttiming.html" title="pg_test_timing" /><link rel="next" href="pgwaldump.html" title="pg_waldump" /></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_upgrade</span></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="pgtesttiming.html" title="pg_test_timing">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 15.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="pgwaldump.html" title="pg_waldump">Next</a></td></tr></table><hr /></div><div class="refentry" id="PGUPGRADE"><div class="titlepage"></div><a id="id-1.9.5.12.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle"><span class="application">pg_upgrade</span></span></h2><p>pg_upgrade — upgrade a <span class="productname">PostgreSQL</span> server instance</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p id="id-1.9.5.12.4.1"><code class="command">pg_upgrade</code> <code class="option">-b</code> <em class="replaceable"><code>oldbindir</code></em> [<code class="option">-B</code> <em class="replaceable"><code>newbindir</code></em>] <code class="option">-d</code> <em class="replaceable"><code>oldconfigdir</code></em> <code class="option">-D</code> <em class="replaceable"><code>newconfigdir</code></em> [<em class="replaceable"><code>option</code></em>...]</p></div></div><div class="refsect1" id="id-1.9.5.12.5"><h2>Description</h2><p> + <span class="application">pg_upgrade</span> (formerly called <span class="application">pg_migrator</span>) allows data + stored in <span class="productname">PostgreSQL</span> data files to be upgraded to a later <span class="productname">PostgreSQL</span> + major version without the data dump/restore typically required for + major version upgrades, e.g., from 9.5.8 to 9.6.4 or from 10.7 to 11.2. + It is not required for minor version upgrades, e.g., from 9.6.2 to 9.6.3 + or from 10.1 to 10.2. + </p><p> + Major PostgreSQL releases regularly add new features that often + change the layout of the system tables, but the internal data storage + format rarely changes. <span class="application">pg_upgrade</span> uses this fact + to perform rapid upgrades by creating new system tables and simply + reusing the old user data files. If a future major release ever + changes the data storage format in a way that makes the old data + format unreadable, <span class="application">pg_upgrade</span> will not be usable + for such upgrades. (The community will attempt to avoid such + situations.) + </p><p> + <span class="application">pg_upgrade</span> does its best to + make sure the old and new clusters are binary-compatible, e.g., by + checking for compatible compile-time settings, including 32/64-bit + binaries. It is important that + any external modules are also binary compatible, though this cannot + be checked by <span class="application">pg_upgrade</span>. + </p><p> + pg_upgrade supports upgrades from 9.2.X and later to the current + major release of <span class="productname">PostgreSQL</span>, including snapshot and beta releases. + </p></div><div class="refsect1" id="id-1.9.5.12.6"><h2>Options</h2><p> + <span class="application">pg_upgrade</span> accepts the following command-line arguments: + + </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">-b</code> <em class="replaceable"><code>bindir</code></em><br /></span><span class="term"><code class="option">--old-bindir=</code><em class="replaceable"><code>bindir</code></em></span></dt><dd><p>the old PostgreSQL executable directory; + environment variable <code class="envar">PGBINOLD</code></p></dd><dt><span class="term"><code class="option">-B</code> <em class="replaceable"><code>bindir</code></em><br /></span><span class="term"><code class="option">--new-bindir=</code><em class="replaceable"><code>bindir</code></em></span></dt><dd><p>the new PostgreSQL executable directory; + default is the directory where <span class="application">pg_upgrade</span> resides; + environment variable <code class="envar">PGBINNEW</code></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>check clusters only, don't change any data</p></dd><dt><span class="term"><code class="option">-d</code> <em class="replaceable"><code>configdir</code></em><br /></span><span class="term"><code class="option">--old-datadir=</code><em class="replaceable"><code>configdir</code></em></span></dt><dd><p>the old database cluster configuration directory; environment + variable <code class="envar">PGDATAOLD</code></p></dd><dt><span class="term"><code class="option">-D</code> <em class="replaceable"><code>configdir</code></em><br /></span><span class="term"><code class="option">--new-datadir=</code><em class="replaceable"><code>configdir</code></em></span></dt><dd><p>the new database cluster configuration directory; environment + variable <code class="envar">PGDATANEW</code></p></dd><dt><span class="term"><code class="option">-j <em class="replaceable"><code>njobs</code></em></code><br /></span><span class="term"><code class="option">--jobs=<em class="replaceable"><code>njobs</code></em></code></span></dt><dd><p>number of simultaneous processes or threads to use + </p></dd><dt><span class="term"><code class="option">-k</code><br /></span><span class="term"><code class="option">--link</code></span></dt><dd><p>use hard links instead of copying files to the new + cluster</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_upgrade</code> will wait for all files + of the upgraded cluster to be written safely to disk. This option + causes <code class="command">pg_upgrade</code> 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 on a production + installation. + </p></dd><dt><span class="term"><code class="option">-o</code> <em class="replaceable"><code>options</code></em><br /></span><span class="term"><code class="option">--old-options</code> <em class="replaceable"><code>options</code></em></span></dt><dd><p>options to be passed directly to the + old <code class="command">postgres</code> command; multiple + option invocations are appended</p></dd><dt><span class="term"><code class="option">-O</code> <em class="replaceable"><code>options</code></em><br /></span><span class="term"><code class="option">--new-options</code> <em class="replaceable"><code>options</code></em></span></dt><dd><p>options to be passed directly to the + new <code class="command">postgres</code> command; multiple + option invocations are appended</p></dd><dt><span class="term"><code class="option">-p</code> <em class="replaceable"><code>port</code></em><br /></span><span class="term"><code class="option">--old-port=</code><em class="replaceable"><code>port</code></em></span></dt><dd><p>the old cluster port number; environment + variable <code class="envar">PGPORTOLD</code></p></dd><dt><span class="term"><code class="option">-P</code> <em class="replaceable"><code>port</code></em><br /></span><span class="term"><code class="option">--new-port=</code><em class="replaceable"><code>port</code></em></span></dt><dd><p>the new cluster port number; environment + variable <code class="envar">PGPORTNEW</code></p></dd><dt><span class="term"><code class="option">-r</code><br /></span><span class="term"><code class="option">--retain</code></span></dt><dd><p>retain SQL and log files even after successful completion + </p></dd><dt><span class="term"><code class="option">-s</code> <em class="replaceable"><code>dir</code></em><br /></span><span class="term"><code class="option">--socketdir=</code><em class="replaceable"><code>dir</code></em></span></dt><dd><p>directory to use for postmaster sockets during upgrade; + default is current working directory; environment + variable <code class="envar">PGSOCKETDIR</code></p></dd><dt><span class="term"><code class="option">-U</code> <em class="replaceable"><code>username</code></em><br /></span><span class="term"><code class="option">--username=</code><em class="replaceable"><code>username</code></em></span></dt><dd><p>cluster's install user name; environment + variable <code class="envar">PGUSER</code></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 internal logging</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>display version information, then exit</p></dd><dt><span class="term"><code class="option">--clone</code></span></dt><dd><p> + Use efficient file cloning (also known as <span class="quote">“<span class="quote">reflinks</span>”</span> on + some systems) instead of copying files to the new cluster. This can + result in near-instantaneous copying of the data files, giving the + speed advantages of <code class="option">-k</code>/<code class="option">--link</code> while + leaving the old cluster untouched. + </p><p> + File cloning is only supported on some operating systems and file + systems. If it is selected but not supported, the + <span class="application">pg_upgrade</span> run will error. At present, it + is supported on Linux (kernel 4.5 or later) with Btrfs and XFS (on + file systems created with reflink support), and on macOS with APFS. + </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, then exit</p></dd></dl></div><p> + </p></div><div class="refsect1" id="id-1.9.5.12.7"><h2>Usage</h2><p> + These are the steps to perform an upgrade + with <span class="application">pg_upgrade</span>: + </p><div class="procedure"><ol class="procedure" type="1"><li class="step"><p class="title"><strong>Optionally move the old cluster</strong></p><p> + If you are using a version-specific installation directory, e.g., + <code class="filename">/opt/PostgreSQL/15</code>, you do not need to move the old cluster. The + graphical installers all use version-specific installation directories. + </p><p> + If your installation directory is not version-specific, e.g., + <code class="filename">/usr/local/pgsql</code>, it is necessary to move the current PostgreSQL install + directory so it does not interfere with the new <span class="productname">PostgreSQL</span> installation. + Once the current <span class="productname">PostgreSQL</span> server is shut down, it is safe to rename the + PostgreSQL installation directory; assuming the old directory is + <code class="filename">/usr/local/pgsql</code>, you can do: + +</p><pre class="programlisting"> +mv /usr/local/pgsql /usr/local/pgsql.old +</pre><p> + to rename the directory. + </p></li><li class="step"><p class="title"><strong>For source installs, build the new version</strong></p><p> + Build the new PostgreSQL source with <code class="command">configure</code> flags that are compatible + with the old cluster. <span class="application">pg_upgrade</span> will check <code class="command">pg_controldata</code> to make + sure all settings are compatible before starting the upgrade. + </p></li><li class="step"><p class="title"><strong>Install the new PostgreSQL binaries</strong></p><p> + Install the new server's binaries and support + files. <span class="application">pg_upgrade</span> is included in a default installation. + </p><p> + For source installs, if you wish to install the new server in a custom + location, use the <code class="literal">prefix</code> variable: + +</p><pre class="programlisting"> +make prefix=/usr/local/pgsql.new install +</pre></li><li class="step"><p class="title"><strong>Initialize the new PostgreSQL cluster</strong></p><p> + Initialize the new cluster using <code class="command">initdb</code>. + Again, use compatible <code class="command">initdb</code> + flags that match the old cluster. Many + prebuilt installers do this step automatically. There is no need to + start the new cluster. + </p></li><li class="step"><p class="title"><strong>Install extension shared object files</strong></p><p> + Many extensions and custom modules, whether from + <code class="filename">contrib</code> or another source, use shared object + files (or DLLs), e.g., <code class="filename">pgcrypto.so</code>. If the old + cluster used these, shared object files matching the new server binary + must be installed in the new cluster, usually via operating system + commands. Do not load the schema definitions, e.g., <code class="command">CREATE + EXTENSION pgcrypto</code>, because these will be duplicated from + the old cluster. If extension updates are available, + <span class="application">pg_upgrade</span> will report this and create + a script that can be run later to update them. + </p></li><li class="step"><p class="title"><strong>Copy custom full-text search files</strong></p><p> + Copy any custom full text search files (dictionary, synonym, + thesaurus, stop words) from the old to the new cluster. + </p></li><li class="step"><p class="title"><strong>Adjust authentication</strong></p><p> + <code class="command">pg_upgrade</code> will connect to the old and new servers several + times, so you might want to set authentication to <code class="literal">peer</code> + in <code class="filename">pg_hba.conf</code> or use a <code class="filename">~/.pgpass</code> file + (see <a class="xref" href="libpq-pgpass.html" title="34.16. The Password File">Section 34.16</a>). + </p></li><li class="step"><p class="title"><strong>Stop both servers</strong></p><p> + Make sure both database servers are stopped using, on Unix, e.g.: + +</p><pre class="programlisting"> +pg_ctl -D /opt/PostgreSQL/9.6 stop +pg_ctl -D /opt/PostgreSQL/15 stop +</pre><p> + + or on Windows, using the proper service names: + +</p><pre class="programlisting"> +NET STOP postgresql-9.6 +NET STOP postgresql-15 +</pre><p> + </p><p> + Streaming replication and log-shipping standby servers must be + running during this shutdown so they receive all changes. + </p></li><li class="step"><p class="title"><strong>Prepare for standby server upgrades</strong></p><p> + If you are upgrading standby servers using methods outlined in section <a class="xref" href="pgupgrade.html#PGUPGRADE-STEP-REPLICAS" title="Upgrade streaming replication and log-shipping standby servers">Step 11</a>, verify that the old standby + servers are caught up by running <span class="application">pg_controldata</span> + against the old primary and standby clusters. Verify that the + <span class="quote">“<span class="quote">Latest checkpoint location</span>”</span> values match in all clusters. + Also, make sure <code class="varname">wal_level</code> is not set to + <code class="literal">minimal</code> in the <code class="filename">postgresql.conf</code> file on the + new primary cluster. + </p></li><li class="step"><p class="title"><strong>Run <span class="application">pg_upgrade</span></strong></p><p> + Always run the <span class="application">pg_upgrade</span> binary of the new server, not the old one. + <span class="application">pg_upgrade</span> requires the specification of the old and new cluster's + data and executable (<code class="filename">bin</code>) directories. You can also specify + user and port values, and whether you want the data files linked or cloned + instead of the default copy behavior. + </p><p> + If you use link mode, the upgrade will be much faster (no file + copying) and use less disk space, but you will not be able to access + your old cluster + once you start the new cluster after the upgrade. Link mode also + requires that the old and new cluster data directories be in the + same file system. (Tablespaces and <code class="filename">pg_wal</code> can be on + different file systems.) + Clone mode provides the same speed and disk space advantages but + does not cause the old cluster to be unusable once the new cluster + is started. Clone mode also requires that the old and new data + directories be in the same file system. This mode is only available + on certain operating systems and file systems. + </p><p> + The <code class="option">--jobs</code> option allows multiple CPU cores to be used + for copying/linking of files and to dump and restore database schemas + in parallel; a good place to start is the maximum of the number of + CPU cores and tablespaces. This option can dramatically reduce the + time to upgrade a multi-database server running on a multiprocessor + machine. + </p><p> + For Windows users, you must be logged into an administrative account, and + then start a shell as the <code class="literal">postgres</code> user and set the proper path: + +</p><pre class="programlisting"> +RUNAS /USER:postgres "CMD.EXE" +SET PATH=%PATH%;C:\Program Files\PostgreSQL\15\bin; +</pre><p> + + and then run <span class="application">pg_upgrade</span> with quoted directories, e.g.: + +</p><pre class="programlisting"> +pg_upgrade.exe + --old-datadir "C:/Program Files/PostgreSQL/9.6/data" + --new-datadir "C:/Program Files/PostgreSQL/15/data" + --old-bindir "C:/Program Files/PostgreSQL/9.6/bin" + --new-bindir "C:/Program Files/PostgreSQL/15/bin" +</pre><p> + + Once started, <code class="command">pg_upgrade</code> will verify the two clusters are compatible + and then do the upgrade. You can use <code class="command">pg_upgrade --check</code> + to perform only the checks, even if the old server is still + running. <code class="command">pg_upgrade --check</code> will also outline any + manual adjustments you will need to make after the upgrade. If you + are going to be using link or clone mode, you should use the option + <code class="option">--link</code> or <code class="option">--clone</code> with + <code class="option">--check</code> to enable mode-specific checks. + <code class="command">pg_upgrade</code> requires write permission in the current directory. + </p><p> + Obviously, no one should be accessing the clusters during the + upgrade. <span class="application">pg_upgrade</span> defaults to running servers + on port 50432 to avoid unintended client connections. + You can use the same port number for both clusters when doing an + upgrade because the old and new clusters will not be running at the + same time. However, when checking an old running server, the old + and new port numbers must be different. + </p><p> + If an error occurs while restoring the database schema, <code class="command">pg_upgrade</code> will + exit and you will have to revert to the old cluster as outlined in <a class="xref" href="pgupgrade.html#PGUPGRADE-STEP-REVERT" title="Reverting to old cluster">Step 17</a> + below. To try <code class="command">pg_upgrade</code> again, you will need to modify the old + cluster so the pg_upgrade schema restore succeeds. If the problem is a + <code class="filename">contrib</code> module, you might need to uninstall the <code class="filename">contrib</code> module from + the old cluster and install it in the new cluster after the upgrade, + assuming the module is not being used to store user data. + </p></li><li class="step" id="PGUPGRADE-STEP-REPLICAS"><p class="title"><strong>Upgrade streaming replication and log-shipping standby servers</strong></p><p> + If you used link mode and have Streaming Replication (see <a class="xref" href="warm-standby.html#STREAMING-REPLICATION" title="27.2.5. Streaming Replication">Section 27.2.5</a>) or Log-Shipping (see <a class="xref" href="warm-standby.html" title="27.2. Log-Shipping Standby Servers">Section 27.2</a>) standby servers, you can follow these steps to + quickly upgrade them. You will not be running <span class="application">pg_upgrade</span> on + the standby servers, but rather <span class="application">rsync</span> on the primary. + Do not start any servers yet. + </p><p> + If you did <span class="emphasis"><em>not</em></span> use link mode, do not have or do not + want to use <span class="application">rsync</span>, or want an easier solution, skip + the instructions in this section and simply recreate the standby + servers once <span class="application">pg_upgrade</span> completes and the new primary + is running. + </p><div class="procedure"><ol class="procedure" type="1"><li class="step"><p class="title"><strong>Install the new PostgreSQL binaries on standby servers</strong></p><p> + Make sure the new binaries and support files are installed on all + standby servers. + </p></li><li class="step"><p class="title"><strong>Make sure the new standby data directories do <span class="emphasis"><em>not</em></span> exist</strong></p><p> + Make sure the new standby data directories do <span class="emphasis"><em>not</em></span> + exist or are empty. If <span class="application">initdb</span> was run, delete + the standby servers' new data directories. + </p></li><li class="step"><p class="title"><strong>Install extension shared object files</strong></p><p> + Install the same extension shared object files on the new standbys + that you installed in the new primary cluster. + </p></li><li class="step"><p class="title"><strong>Stop standby servers</strong></p><p> + If the standby servers are still running, stop them now using the + above instructions. + </p></li><li class="step"><p class="title"><strong>Save configuration files</strong></p><p> + Save any configuration files from the old standbys' configuration + directories you need to keep, e.g., <code class="filename">postgresql.conf</code> + (and any files included by it), <code class="filename">postgresql.auto.conf</code>, + <code class="literal">pg_hba.conf</code>, because these will be overwritten + or removed in the next step. + </p></li><li class="step"><p class="title"><strong>Run <span class="application">rsync</span></strong></p><p> + When using link mode, standby servers can be quickly upgraded using + <span class="application">rsync</span>. To accomplish this, from a directory on + the primary server that is above the old and new database cluster + directories, run this on the <span class="emphasis"><em>primary</em></span> for each standby + server: + +</p><pre class="programlisting"> +rsync --archive --delete --hard-links --size-only --no-inc-recursive old_cluster new_cluster remote_dir +</pre><p> + + where <code class="option">old_cluster</code> and <code class="option">new_cluster</code> are relative + to the current directory on the primary, and <code class="option">remote_dir</code> + is <span class="emphasis"><em>above</em></span> the old and new cluster directories + on the standby. The directory structure under the specified + directories on the primary and standbys must match. Consult the + <span class="application">rsync</span> manual page for details on specifying the + remote directory, e.g., + +</p><pre class="programlisting"> +rsync --archive --delete --hard-links --size-only --no-inc-recursive /opt/PostgreSQL/9.5 \ + /opt/PostgreSQL/9.6 standby.example.com:/opt/PostgreSQL +</pre><p> + + You can verify what the command will do using + <span class="application">rsync</span>'s <code class="option">--dry-run</code> option. While + <span class="application">rsync</span> must be run on the primary for at least one + standby, it is possible to run <span class="application">rsync</span> on an upgraded + standby to upgrade other standbys, as long as the upgraded standby + has not been started. + </p><p> + What this does is to record the links created by + <span class="application">pg_upgrade</span>'s link mode that connect files in the + old and new clusters on the primary server. It then finds matching + files in the standby's old cluster and creates links for them in the + standby's new cluster. Files that were not linked on the primary + are copied from the primary to the standby. (They are usually + small.) This provides rapid standby upgrades. Unfortunately, + <span class="application">rsync</span> needlessly copies files associated with + temporary and unlogged tables because these files don't normally + exist on standby servers. + </p><p> + If you have tablespaces, you will need to run a similar + <span class="application">rsync</span> command for each tablespace directory, e.g.: + +</p><pre class="programlisting"> +rsync --archive --delete --hard-links --size-only --no-inc-recursive /vol1/pg_tblsp/PG_9.5_201510051 \ + /vol1/pg_tblsp/PG_9.6_201608131 standby.example.com:/vol1/pg_tblsp +</pre><p> + + If you have relocated <code class="filename">pg_wal</code> outside the data + directories, <span class="application">rsync</span> must be run on those directories + too. + </p></li><li class="step"><p class="title"><strong>Configure streaming replication and log-shipping standby servers</strong></p><p> + Configure the servers for log shipping. (You do not need to run + <code class="function">pg_backup_start()</code> and <code class="function">pg_backup_stop()</code> + or take a file system backup as the standbys are still synchronized + with the primary.) Replication slots are not copied and must + be recreated. + </p></li></ol></div></li><li class="step"><p class="title"><strong>Restore <code class="filename">pg_hba.conf</code></strong></p><p> + If you modified <code class="filename">pg_hba.conf</code>, restore its original settings. + It might also be necessary to adjust other configuration files in the new + cluster to match the old cluster, e.g., <code class="filename">postgresql.conf</code> + (and any files included by it), <code class="filename">postgresql.auto.conf</code>. + </p></li><li class="step"><p class="title"><strong>Start the new server</strong></p><p> + The new server can now be safely started, and then any + <span class="application">rsync</span>'ed standby servers. + </p></li><li class="step"><p class="title"><strong>Post-upgrade processing</strong></p><p> + If any post-upgrade processing is required, pg_upgrade will issue + warnings as it completes. It will also generate script files that must + be run by the administrator. The script files will connect to each + database that needs post-upgrade processing. Each script should be + run using: + +</p><pre class="programlisting"> +psql --username=postgres --file=script.sql postgres +</pre><p> + + The scripts can be run in any order and can be deleted once they have + been run. + </p><div class="caution"><h3 class="title">Caution</h3><p> + In general it is unsafe to access tables referenced in rebuild scripts + until the rebuild scripts have run to completion; doing so could yield + incorrect results or poor performance. Tables not referenced in rebuild + scripts can be accessed immediately. + </p></div></li><li class="step"><p class="title"><strong>Statistics</strong></p><p> + Because optimizer statistics are not transferred by <code class="command">pg_upgrade</code>, you will + be instructed to run a command to regenerate that information at the end + of the upgrade. You might need to set connection parameters to + match your new cluster. + </p></li><li class="step"><p class="title"><strong>Delete old cluster</strong></p><p> + Once you are satisfied with the upgrade, you can delete the old + cluster's data directories by running the script mentioned when + <code class="command">pg_upgrade</code> completes. (Automatic deletion is not + possible if you have user-defined tablespaces inside the old data + directory.) You can also delete the old installation directories + (e.g., <code class="filename">bin</code>, <code class="filename">share</code>). + </p></li><li class="step" id="PGUPGRADE-STEP-REVERT"><p class="title"><strong>Reverting to old cluster</strong></p><p> + If, after running <code class="command">pg_upgrade</code>, you wish to revert to the old cluster, + there are several options: + + </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> + If the <code class="option">--check</code> option was used, the old cluster + was unmodified; it can be restarted. + </p></li><li class="listitem"><p> + If the <code class="option">--link</code> option was <span class="emphasis"><em>not</em></span> + used, the old cluster was unmodified; it can be restarted. + </p></li><li class="listitem"><p> + If the <code class="option">--link</code> option was used, the data + files might be shared between the old and new cluster: + + </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p> + If <code class="command">pg_upgrade</code> aborted before linking started, + the old cluster was unmodified; it can be restarted. + </p></li><li class="listitem"><p> + If you did <span class="emphasis"><em>not</em></span> start the new cluster, the old + cluster was unmodified except that, when linking started, a + <code class="literal">.old</code> suffix was appended to + <code class="filename">$PGDATA/global/pg_control</code>. To reuse the old + cluster, remove the <code class="filename">.old</code> suffix from + <code class="filename">$PGDATA/global/pg_control</code>; you can then restart + the old cluster. + </p></li><li class="listitem"><p> + If you did start the new cluster, it has written to shared files + and it is unsafe to use the old cluster. The old cluster will + need to be restored from backup in this case. + </p></li></ul></div></li></ul></div></li></ol></div></div><div class="refsect1" id="id-1.9.5.12.8"><h2>Notes</h2><p> + <span class="application">pg_upgrade</span> creates various working files, such + as schema dumps, stored within <code class="filename">pg_upgrade_output.d</code> in + the directory of the new cluster. Each run creates a new subdirectory named + with a timestamp formatted as per ISO 8601 + (<code class="literal">%Y%m%dT%H%M%S</code>), where all its generated files are + stored. + <code class="filename">pg_upgrade_output.d</code> and its contained files will be + removed automatically if <span class="application">pg_upgrade</span> completes + successfully; but in the event of trouble, the files there may provide + useful debugging information. + </p><p> + <span class="application">pg_upgrade</span> launches short-lived postmasters in + the old and new data directories. Temporary Unix socket files for + communication with these postmasters are, by default, made in the current + working directory. In some situations the path name for the current + directory might be too long to be a valid socket name. In that case you + can use the <code class="option">-s</code> option to put the socket files in some + directory with a shorter path name. For security, be sure that that + directory is not readable or writable by any other users. + (This is not supported on Windows.) + </p><p> + All failure, rebuild, and reindex cases will be reported by + <span class="application">pg_upgrade</span> if they affect your installation; + post-upgrade scripts to rebuild tables and indexes will be + generated automatically. If you are trying to automate the upgrade + of many clusters, you should find that clusters with identical database + schemas require the same post-upgrade steps for all cluster upgrades; + this is because the post-upgrade steps are based on the database + schemas, and not user data. + </p><p> + For deployment testing, create a schema-only copy of the old cluster, + insert dummy data, and upgrade that. + </p><p> + <span class="application">pg_upgrade</span> does not support upgrading of databases + containing table columns using these <code class="type">reg*</code> OID-referencing system data types: + </p><table border="0" summary="Simple list" class="simplelist"><tr><td><code class="type">regcollation</code></td></tr><tr><td><code class="type">regconfig</code></td></tr><tr><td><code class="type">regdictionary</code></td></tr><tr><td><code class="type">regnamespace</code></td></tr><tr><td><code class="type">regoper</code></td></tr><tr><td><code class="type">regoperator</code></td></tr><tr><td><code class="type">regproc</code></td></tr><tr><td><code class="type">regprocedure</code></td></tr></table><p> + (<code class="type">regclass</code>, <code class="type">regrole</code>, and <code class="type">regtype</code> can be upgraded.) + </p><p> + If you want to use link mode and you do not want your old cluster + to be modified when the new cluster is started, consider using the clone mode. + If that is not available, make a copy of the + old cluster and upgrade that in link mode. To make a valid copy + of the old cluster, use <code class="command">rsync</code> to create a dirty + copy of the old cluster while the server is running, then shut down + the old server and run <code class="command">rsync --checksum</code> again to update the + copy with any changes to make it consistent. (<code class="option">--checksum</code> + is necessary because <code class="command">rsync</code> only has file modification-time + granularity of one second.) You might want to exclude some + files, e.g., <code class="filename">postmaster.pid</code>, as documented in <a class="xref" href="continuous-archiving.html#BACKUP-LOWLEVEL-BASE-BACKUP" title="26.3.3. Making a Base Backup Using the Low Level API">Section 26.3.3</a>. If your file system supports + file system snapshots or copy-on-write file copies, you can use that + to make a backup of the old cluster and tablespaces, though the snapshot + and copies must be created simultaneously or while the database server + is down. + </p></div><div class="refsect1" id="id-1.9.5.12.9"><h2>See Also</h2><span class="simplelist"><a class="xref" href="app-initdb.html" title="initdb"><span class="refentrytitle"><span class="application">initdb</span></span></a>, <a class="xref" href="app-pg-ctl.html" title="pg_ctl"><span class="refentrytitle"><span class="application">pg_ctl</span></span></a>, <a class="xref" href="app-pgdump.html" title="pg_dump"><span class="refentrytitle"><span class="application">pg_dump</span></span></a>, <a class="xref" href="app-postgres.html" title="postgres"><span class="refentrytitle"><span class="application">postgres</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="pgtesttiming.html" title="pg_test_timing">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="pgwaldump.html" title="pg_waldump">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="application">pg_test_timing</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 15.5 Documentation">Home</a></td><td width="40%" align="right" valign="top"> <span class="application">pg_waldump</span></td></tr></table></div></body></html>
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