1PG_UPGRADE(1) PostgreSQL 12.6 Documentation PG_UPGRADE(1)
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6 pg_upgrade - upgrade a PostgreSQL server instance
7
9 pg_upgrade -b oldbindir -B newbindir -d oldconfigdir -D newconfigdir
10 [option...]
11
13 pg_upgrade (formerly called pg_migrator) allows data stored in
14 PostgreSQL data files to be upgraded to a later PostgreSQL major
15 version without the data dump/reload typically required for major
16 version upgrades, e.g., from 9.5.8 to 9.6.4 or from 10.7 to 11.2. It is
17 not required for minor version upgrades, e.g., from 9.6.2 to 9.6.3 or
18 from 10.1 to 10.2.
19 Major PostgreSQL releases regularly add new features that often change
21 the layout of the system tables, but the internal data storage format
22 rarely changes. pg_upgrade uses this fact to perform rapid upgrades by
23 creating new system tables and simply reusing the old user data files.
24 If a future major release ever changes the data storage format in a way
25 that makes the old data format unreadable, pg_upgrade will not be
26 usable for such upgrades. (The community will attempt to avoid such
27 situations.)
28 pg_upgrade does its best to make sure the old and new clusters are
30 binary-compatible, e.g., by checking for compatible compile-time
31 settings, including 32/64-bit binaries. It is important that any
32 external modules are also binary compatible, though this cannot be
33 checked by pg_upgrade.
34 pg_upgrade supports upgrades from 8.4.X and later to the current major
36 release of PostgreSQL, including snapshot and beta releases.
37
39 pg_upgrade accepts the following command-line arguments:
40 -b bindir
42 --old-bindir=bindir
43 the old PostgreSQL executable directory; environment variable
44 PGBINOLD
45 -B bindir
47 --new-bindir=bindir
48 the new PostgreSQL executable directory; environment variable
49 PGBINNEW
50 -c
52 --check
53 check clusters only, don't change any data
54 -d configdir
56 --old-datadir=configdir
57 the old database cluster configuration directory; environment
58 variable PGDATAOLD
59 -D configdir
61 --new-datadir=configdir
62 the new database cluster configuration directory; environment
63 variable PGDATANEW
64 -j njobs
66 --jobs=njobs
67 number of simultaneous processes or threads to use
68 -k
70 --link
71 use hard links instead of copying files to the new cluster
72 -o options
74 --old-options options
75 options to be passed directly to the old postgres command; multiple
76 option invocations are appended
77 -O options
79 --new-options options
80 options to be passed directly to the new postgres command; multiple
81 option invocations are appended
82 -p port
84 --old-port=port
85 the old cluster port number; environment variable PGPORTOLD
86 -P port
88 --new-port=port
89 the new cluster port number; environment variable PGPORTNEW
90 -r
92 --retain
93 retain SQL and log files even after successful completion
94 -s dir
96 --socketdir=dir
97 directory to use for postmaster sockets during upgrade; default is
98 current working directory; environment variable PGSOCKETDIR
99 -U username
101 --username=username
102 cluster's install user name; environment variable PGUSER
103 -v
105 --verbose
106 enable verbose internal logging
107 -V
109 --version
110 display version information, then exit
111 --clone
113 Use efficient file cloning (also known as “reflinks” on some
114 systems) instead of copying files to the new cluster. This can
115 result in near-instantaneous copying of the data files, giving the
116 speed advantages of -k/--link while leaving the old cluster
117 untouched.
118 File cloning is only supported on some operating systems and file
120 systems. If it is selected but not supported, the pg_upgrade run
121 will error. At present, it is supported on Linux (kernel 4.5 or
122 later) with Btrfs and XFS (on file systems created with reflink
123 support), and on macOS with APFS.
124 -?
126 --help
127 show help, then exit
128
130 These are the steps to perform an upgrade with pg_upgrade:
131 1. Optionally move the old cluster: If you are using a
133 version-specific installation directory, e.g., /opt/PostgreSQL/12,
134 you do not need to move the old cluster. The graphical installers
135 all use version-specific installation directories.
136 If your installation directory is not version-specific, e.g.,
138 /usr/local/pgsql, it is necessary to move the current PostgreSQL
139 install directory so it does not interfere with the new PostgreSQL
140 installation. Once the current PostgreSQL server is shut down, it
141 is safe to rename the PostgreSQL installation directory; assuming
142 the old directory is /usr/local/pgsql, you can do:
143 mv /usr/local/pgsql /usr/local/pgsql.old
145 to rename the directory.
147 2. For source installs, build the new version: Build the new
149 PostgreSQL source with configure flags that are compatible with the
150 old cluster. pg_upgrade will check pg_controldata to make sure all
151 settings are compatible before starting the upgrade.
152 3. Install the new PostgreSQL binaries: Install the new server's
154 binaries and support files. pg_upgrade is included in a default
155 installation.
156 For source installs, if you wish to install the new server in a
158 custom location, use the prefix variable:
159 make prefix=/usr/local/pgsql.new install
161 4. Initialize the new PostgreSQL cluster: Initialize the new cluster
163 using initdb. Again, use compatible initdb flags that match the old
164 cluster. Many prebuilt installers do this step automatically. There
165 is no need to start the new cluster.
166 5. Install custom shared object files: Install any custom shared
168 object files (or DLLs) used by the old cluster into the new
169 cluster, e.g., pgcrypto.so, whether they are from contrib or some
170 other source. Do not install the schema definitions, e.g., CREATE
171 EXTENSION pgcrypto, because these will be upgraded from the old
172 cluster. Also, any custom full text search files (dictionary,
173 synonym, thesaurus, stop words) must also be copied to the new
174 cluster.
175 6. Adjust authentication: pg_upgrade will connect to the old and new
177 servers several times, so you might want to set authentication to
178 peer in pg_hba.conf or use a ~/.pgpass file (see Section 33.15).
179 7. Stop both servers: Make sure both database servers are stopped
181 using, on Unix, e.g.:
182 pg_ctl -D /opt/PostgreSQL/9.6 stop
184 pg_ctl -D /opt/PostgreSQL/12 stop
185 or on Windows, using the proper service names:
187 NET STOP postgresql-9.6
189 NET STOP postgresql-12
190 Streaming replication and log-shipping standby servers can remain
192 running until a later step.
193 8. Prepare for standby server upgrades: If you are upgrading standby
195 servers using methods outlined in section Step 10, verify that the
196 old standby servers are caught up by running pg_controldata against
197 the old primary and standby clusters. Verify that the “Latest
198 checkpoint location” values match in all clusters. (There will be a
199 mismatch if old standby servers were shut down before the old
200 primary or if the old standby servers are still running.) Also,
201 make sure wal_level is not set to minimal in the postgresql.conf
202 file on the new primary cluster.
203 9. Run pg_upgrade: Always run the pg_upgrade binary of the new server,
205 not the old one. pg_upgrade requires the specification of the old
206 and new cluster's data and executable (bin) directories. You can
207 also specify user and port values, and whether you want the data
208 files linked or cloned instead of the default copy behavior.
209 If you use link mode, the upgrade will be much faster (no file
211 copying) and use less disk space, but you will not be able to
212 access your old cluster once you start the new cluster after the
213 upgrade. Link mode also requires that the old and new cluster data
214 directories be in the same file system. (Tablespaces and pg_wal can
215 be on different file systems.) Clone mode provides the same speed
216 and disk space advantages but does not cause the old cluster to be
217 unusable once the new cluster is started. Clone mode also requires
218 that the old and new data directories be in the same file system.
219 This mode is only available on certain operating systems and file
220 systems.
221 The --jobs option allows multiple CPU cores to be used for
223 copying/linking of files and to dump and reload database schemas in
224 parallel; a good place to start is the maximum of the number of CPU
225 cores and tablespaces. This option can dramatically reduce the time
226 to upgrade a multi-database server running on a multiprocessor
227 machine.
228 For Windows users, you must be logged into an administrative
230 account, and then start a shell as the postgres user and set the
231 proper path:
232 RUNAS /USER:postgres "CMD.EXE"
234 SET PATH=%PATH%;C:\Program Files\PostgreSQL\12\bin;
235 and then run pg_upgrade with quoted directories, e.g.:
237 pg_upgrade.exe
239 --old-datadir "C:/Program Files/PostgreSQL/9.6/data"
240 --new-datadir "C:/Program Files/PostgreSQL/12/data"
241 --old-bindir "C:/Program Files/PostgreSQL/9.6/bin"
242 --new-bindir "C:/Program Files/PostgreSQL/12/bin"
243 Once started, pg_upgrade will verify the two clusters are
245 compatible and then do the upgrade. You can use pg_upgrade --check
246 to perform only the checks, even if the old server is still
247 running. pg_upgrade --check will also outline any manual
248 adjustments you will need to make after the upgrade. If you are
249 going to be using link or clone mode, you should use the option
250 --link or --clone with --check to enable mode-specific checks.
251 pg_upgrade requires write permission in the current directory.
252 Obviously, no one should be accessing the clusters during the
254 upgrade. pg_upgrade defaults to running servers on port 50432 to
255 avoid unintended client connections. You can use the same port
256 number for both clusters when doing an upgrade because the old and
257 new clusters will not be running at the same time. However, when
258 checking an old running server, the old and new port numbers must
259 be different.
260 If an error occurs while restoring the database schema, pg_upgrade
262 will exit and you will have to revert to the old cluster as
263 outlined in Step 16 below. To try pg_upgrade again, you will need
264 to modify the old cluster so the pg_upgrade schema restore
265 succeeds. If the problem is a contrib module, you might need to
266 uninstall the contrib module from the old cluster and install it in
267 the new cluster after the upgrade, assuming the module is not being
268 used to store user data.
269 10. Upgrade streaming replication and log-shipping standby servers: If
271 you used link mode and have Streaming Replication (see
272 Section 26.2.5) or Log-Shipping (see Section 26.2) standby servers,
273 you can follow these steps to quickly upgrade them. You will not be
274 running pg_upgrade on the standby servers, but rather rsync on the
275 primary. Do not start any servers yet.
276 If you did not use link mode, do not have or do not want to use
278 rsync, or want an easier solution, skip the instructions in this
279 section and simply recreate the standby servers once pg_upgrade
280 completes and the new primary is running. Install the new
281 PostgreSQL binaries on standby servers: Make sure the new binaries
282 and support files are installed on all standby servers. Make sure
283 the new standby data directories do not exist: Make sure the new
284 standby data directories do not exist or are empty. If initdb was
285 run, delete the standby servers' new data directories. Install
286 custom shared object files: Install the same custom shared object
287 files on the new standbys that you installed in the new primary
288 cluster. Stop standby servers: If the standby servers are still
289 running, stop them now using the above instructions. Save
290 configuration files: Save any configuration files from the old
291 standbys' configuration directories you need to keep, e.g.,
292 postgresql.conf (and any files included by it),
293 postgresql.auto.conf, pg_hba.conf, because these will be
294 overwritten or removed in the next step. Run rsync: When using
295 link mode, standby servers can be quickly upgraded using rsync. To
296 accomplish this, from a directory on the primary server that is
297 above the old and new database cluster directories, run this on the
298 primary for each standby server:
299 rsync --archive --delete --hard-links --size-only --no-inc-recursive old_cluster new_cluster remote_dir
301 where old_cluster and new_cluster are relative to the current
303 directory on the primary, and remote_dir is above the old and new
304 cluster directories on the standby. The directory structure under
305 the specified directories on the primary and standbys must match.
306 Consult the rsync manual page for details on specifying the remote
307 directory, e.g.,
308 rsync --archive --delete --hard-links --size-only --no-inc-recursive /opt/PostgreSQL/9.5 \
310 /opt/PostgreSQL/9.6 standby.example.com:/opt/PostgreSQL
311 You can verify what the command will do using rsync's --dry-run
313 option. While rsync must be run on the primary for at least one
314 standby, it is possible to run rsync on an upgraded standby to
315 upgrade other standbys, as long as the upgraded standby has not
316 been started.
317 What this does is to record the links created by pg_upgrade's link
319 mode that connect files in the old and new clusters on the primary
320 server. It then finds matching files in the standby's old cluster
321 and creates links for them in the standby's new cluster. Files that
322 were not linked on the primary are copied from the primary to the
323 standby. (They are usually small.) This provides rapid standby
324 upgrades. Unfortunately, rsync needlessly copies files associated
325 with temporary and unlogged tables because these files don't
326 normally exist on standby servers.
327 If you have tablespaces, you will need to run a similar rsync
329 command for each tablespace directory, e.g.:
330 rsync --archive --delete --hard-links --size-only --no-inc-recursive /vol1/pg_tblsp/PG_9.5_201510051 \
332 /vol1/pg_tblsp/PG_9.6_201608131 standby.example.com:/vol1/pg_tblsp
333 If you have relocated pg_wal outside the data directories, rsync
335 must be run on those directories too. Configure streaming
336 replication and log-shipping standby servers: Configure the servers
337 for log shipping. (You do not need to run pg_start_backup() and
338 pg_stop_backup() or take a file system backup as the standbys are
339 still synchronized with the primary.)
340 11. Restore pg_hba.conf: If you modified pg_hba.conf, restore its
342 original settings. It might also be necessary to adjust other
343 configuration files in the new cluster to match the old cluster,
344 e.g., postgresql.conf (and any files included by it),
345 postgresql.auto.conf.
346 12. Start the new server: The new server can now be safely started,
348 and then any rsync'ed standby servers.
349 13. Post-upgrade processing: If any post-upgrade processing is
351 required, pg_upgrade will issue warnings as it completes. It will
352 also generate script files that must be run by the administrator.
353 The script files will connect to each database that needs
354 post-upgrade processing. Each script should be run using:
355 psql --username=postgres --file=script.sql postgres
357 The scripts can be run in any order and can be deleted once they
359 have been run.
360 Caution
362 In general it is unsafe to access tables referenced in rebuild
363 scripts until the rebuild scripts have run to completion; doing
364 so could yield incorrect results or poor performance. Tables
365 not referenced in rebuild scripts can be accessed immediately.
366 14. Statistics: Because optimizer statistics are not transferred by
368 pg_upgrade, you will be instructed to run a command to regenerate
369 that information at the end of the upgrade. You might need to set
370 connection parameters to match your new cluster.
371 15. Delete old cluster: Once you are satisfied with the upgrade, you
373 can delete the old cluster's data directories by running the script
374 mentioned when pg_upgrade completes. (Automatic deletion is not
375 possible if you have user-defined tablespaces inside the old data
376 directory.) You can also delete the old installation directories
377 (e.g., bin, share).
378 16. Reverting to old cluster: If, after running pg_upgrade, you wish
380 to revert to the old cluster, there are several options:
381 · If the --check option was used, the old cluster was unmodified;
383 it can be restarted.
384 · If the --link option was not used, the old cluster was
386 unmodified; it can be restarted.
387 · If the --link option was used, the data files might be shared
389 between the old and new cluster:
390 · If pg_upgrade aborted before linking started, the old
392 cluster was unmodified; it can be restarted.
393 · If you did not start the new cluster, the old cluster was
395 unmodified except that, when linking started, a .old suffix
396 was appended to $PGDATA/global/pg_control. To reuse the old
397 cluster, remove the .old suffix from
398 $PGDATA/global/pg_control; you can then restart the old
399 cluster.
400 · If you did start the new cluster, it has written to shared
402 files and it is unsafe to use the old cluster. The old
403 cluster will need to be restored from backup in this case.
404
408 pg_upgrade creates various working files, such as schema dumps, in the
409 current working directory. For security, be sure that that directory is
410 not readable or writable by any other users.
411 pg_upgrade launches short-lived postmasters in the old and new data
413 directories. Temporary Unix socket files for communication with these
414 postmasters are, by default, made in the current working directory. In
415 some situations the path name for the current directory might be too
416 long to be a valid socket name. In that case you can use the -s option
417 to put the socket files in some directory with a shorter path name. For
418 security, be sure that that directory is not readable or writable by
419 any other users. (This is not relevant on Windows.)
420 All failure, rebuild, and reindex cases will be reported by pg_upgrade
422 if they affect your installation; post-upgrade scripts to rebuild
423 tables and indexes will be generated automatically. If you are trying
424 to automate the upgrade of many clusters, you should find that clusters
425 with identical database schemas require the same post-upgrade steps for
426 all cluster upgrades; this is because the post-upgrade steps are based
427 on the database schemas, and not user data.
428 For deployment testing, create a schema-only copy of the old cluster,
430 insert dummy data, and upgrade that.
431 pg_upgrade does not support upgrading of databases containing table
433 columns using these reg* OID-referencing system data types: regproc,
434 regprocedure, regoper, regoperator, regconfig, and regdictionary.
435 (regtype can be upgraded.)
436 If you are upgrading a pre-PostgreSQL 9.2 cluster that uses a
438 configuration-file-only directory, you must pass the real data
439 directory location to pg_upgrade, and pass the configuration directory
440 location to the server, e.g., -d /real-data-directory -o '-D
441 /configuration-directory'.
442 If using a pre-9.1 old server that is using a non-default Unix-domain
444 socket directory or a default that differs from the default of the new
445 cluster, set PGHOST to point to the old server's socket location. (This
446 is not relevant on Windows.)
447 If you want to use link mode and you do not want your old cluster to be
449 modified when the new cluster is started, consider using the clone
450 mode. If that is not available, make a copy of the old cluster and
451 upgrade that in link mode. To make a valid copy of the old cluster, use
452 rsync to create a dirty copy of the old cluster while the server is
453 running, then shut down the old server and run rsync --checksum again
454 to update the copy with any changes to make it consistent. (--checksum
455 is necessary because rsync only has file modification-time granularity
456 of one second.) You might want to exclude some files, e.g.,
457 postmaster.pid, as documented in Section 25.3.3. If your file system
458 supports file system snapshots or copy-on-write file copies, you can
459 use that to make a backup of the old cluster and tablespaces, though
460 the snapshot and copies must be created simultaneously or while the
461 database server is down.
462
464 initdb(1), pg_ctl(1), pg_dump(1), postgres(1)
465PostgreSQL 12.6 2021 PG_UPGRADE(1)