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Manuale:Fare una copia di sicurezza di una wiki

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È importante effettuare regolari backups dei dati del proprio wiki (dati e file). Questa pagina fornisce una panoramica del processo di backup per un wiki MediaWiki tipico; probabilmente si vorrà ideare un proprio script di backup o un programma per adattarlo alle dimensioni del wiki e alle proprie esigenze individuali.

Help:Export è un modo rapido e semplice per salvare tutte le pagine del tuo wiki.

Panoramica

MediaWiki memorizza i dati importanti in due luoghi:

Database
pagine ed i loro contenuti, utenti e le loro configurazioni, metadata, indici di ricerca, etc.
File system
files di configurazione del software, skins personalizzate, estensioni, immagini (incluse immagini cancellate), etc.

Occorre mettere il wiki in modalità read-only (solo-lettura) prima di creare il backup - vedi $wgReadOnly . Questo garantirà che tutte le parti del proprio backup siano consistenti (alcune delle estensioni installate possono scrivere dati).

Trasferimento file

Occorrerà scegliere un metodo per il trasferimento dei files dal server di partenza:

  • I dati non privati si possono semplicemente pubblicare su archive.org e/o in una directory dumps/ del proprio server web.
  • SCP (o WinSCP), SFTP/FTP o altri protocolli di trasferimento dati di propria scelta.
  • La società di hosting di norma fornisce un file manager utilizzabile da una interfaccia via browser web, verificare con il proprio provider.

Database

La maggior parte dei dati critici del wiki è memorizzata nel database. Quando si usa il backend predefinito MySQL o MariaDB, il database può essere scaricato in un file di script che può essere usato in seguito per ricreare da zero il database e tutti i dati in esso contenuti. If your wiki is currently offline, its database can be backed up by simply copying the database file.

When using the default MySQL or MariaDB backend, the database can be dumped into a script file which can be used later to recreate the database and all the data in it from scratch.

MySQL

Automysqlbackup

Vedere il pacchetto in Debian: 

$ apt show automysqlbackup
[...]
Description: automysqlbackup creates backup every day, week and month for all of your MySQL database, to a configured folder. There's nothing to do but to install this package, and you'll rest assured that you have a way to go back in the history of your database.
[...]

Installare il pacchetto: 

# apt install automysqlbackup

Tutto il tuo database sarà salvato in /var/lib/automysqlbackup/: 

$ find /var/lib/automysqlbackup/
/var/lib/automysqlbackup/
/var/lib/automysqlbackup/weekly
/var/lib/automysqlbackup/weekly/my_wiki
/var/lib/automysqlbackup/weekly/my_wiki/my_wiki_week.18.2016-05-07_15h32m.sql.gz
/var/lib/automysqlbackup/monthly
/var/lib/automysqlbackup/daily
/var/lib/automysqlbackup/daily/my_wiki

Backup manuale: 

# automysqlbackup

Ripristinare un database: 

gunzip < /var/lib/automysqlbackup/weekly/my_wiki/my_wiki_week.18.2016-05-07_15h32m.sql.gz|mysql -uUSER -pPASSWORD my_wiki

Per altre distribuzioni, vedere su Sourceforge.

Mysqldump dalla linea di comando

Il modo più comodo per creare un file di dump del database di cui si vuole fare il backup è usare lo strumento standard di dump di MySQL mysqldump dalla riga di comando. Assicuratevi di aver impostato correttamente i parametri o potreste avere difficoltà a ripristinare il database. A seconda delle dimensioni del database, mysqldump potrebbe richiedere un tempo considerevole.

First insert the following line into LocalSettings.php 

$wgReadOnly = 'Dumping Database, Access will be restored shortly';

this can be removed as soon as the dump is completed.

Esempio del comando ad eseguire nella shell di Linux/UNIX: 

mysqldump -h hostname -u userid -p --default-character-set=charset dbname > backup.sql

Substituting hostname, userid, charset, and dbname as appropriate. Tutti e quattro si possono trovare nel tuo file LocalSettings.php (LSP). hostname may be found under $wgDBserver ; by default it is localhost. userid may be found under $wgDBuser , charset may be found under $wgDBTableOptions , where it is listed after DEFAULT CHARSET=. If charset is not specified mysqldump will likely use the default of utf8, or if using an older version of MySQL, latin1. While dbname may be found under $wgDBname . After running this line from the command line mysqldump will prompt for the server password (which may be found under Manual:$wgDBpassword in LSP).

See mysqldump for a full list of command line parameters.

The output from mysqldump can instead be piped to gzip, for a smaller output file, as follows 

mysqldump -h hostname -u userid -p dbname | gzip > backup.sql.gz

Some newer versions of MySQL might show an error about tablespaces and PROCESS privilege. MediaWiki does not use tablespaces. The solution is to add the --no-tablespaces option to the command: 

mysqldump --no-tablespaces -h hostname -u userid -p dbname | gzip > backup.sql.gz

A similar mysqldump command can be used to produce XML output instead, by including the --xml parameter. 

mysqldump -h hostname -u userid -p --xml dbname > backup.xml

and to compress the file with a pipe to gzip 

mysqldump -h hostname -u userid -p --xml dbname | gzip > backup.xml.gz

Additional options you should consider using with mysqldump for a backup includes the following.

Additional Mysqldump Options
Option Description
--default-character-set Specify default character set
--no-tablespaces Do not write CREATE LOGFILE GROUP or CREATE TABLESPACE statements in output
--single-transaction Issue a BEGIN SQL statement before dumping data from server
--triggers Dump triggers for each dumped table
--routines Dump stored routines (procedures and functions) from dumped databases
--events Dump events from dumped databases
--add-drop-table Add DROP DATABASE statement before each CREATE DATABASE statement
--create-options Include MySQL-specific table options in CREATE TABLE statements
--extended-insert Use multiple-row INSERT syntax

If you do not use --single-transaction, then you should consider using the --lock-tables and --add-locks options.

Due to an unexpected change in MySQL versions 5.7.41 and 8.0.32 in February 2023, the --single-transaction option required the backup user to have RELOAD or FLUSH_TABLES privileges. The issue was fixed in MySQL versions 5.7.42 and 8.0.33. See MySQL Bug 109685 and Ubuntu Bug 2003866 for details.

Remember to backup the additional file system components used by the wiki that might be required during a restore, like images, logo, skins and extensions.

Avviare mysqldump con Cron

Cron is the time-based job scheduler in Unix-like computer operating systems. Cron enables users to schedule jobs (commands or shell scripts) to run periodically at certain times or dates.

A sample command that you may run from a crontab may look like this: 

nice -n 19 mysqldump -u $USER --password=$PASSWORD $DATABASE -c | nice -n 19 gzip -9 > ~/backup/wiki-$DATABASE-$(date '+%Y%m%d').sql.gz

The nice -n 19 lowers the priority of the process.

Use valid values for $USER, $PASSWORD, and $DATABASE. This will write a backup file with the weekday in the filename so you would have a rolling set of backups. If you want to save the files and extensions as well, you might want to use this one.

Attenzione Attenzione: Do not attempt to back up your MediaWiki database using mysqlhotcopy. The table format used by MediaWiki cannot be backed up with this tool, and it will fail silently!

If you want to add this task in Cron through Cpanel then you must escape the character "%" 

/usr/bin/mysqldump -u $USER --password=$PASSWORD $DATABASE -c | /bin/gzip > ~/backup/wiki-$DATABASE-$(date '+\%Y\%m\%d').sql.gz

or you will get an error: 

/bin/sh: -c: line 0: unexpected EOF while looking for matching `''
/bin/sh: -c: line 1: syntax error: unexpected end of file

Running mysqldump with Systemd

Systemd unifies service configurations and control. Timers are systemd unit files that control service files or events. Timers can be used as an alternative to cron. An example of systemd unit files and backup script is shown below.

wiki-backup.timer

The following timer runs the wiki-backup service at 5:10 AM every morning. 

$ cat /etc/systemd/system/wiki-backup.timer

[Unit]
Description=Run the backup service once a day
Documentation=...

[Timer]
OnCalendar=*-*-* 05:10:00
RandomizedDelaySec=600
Persistent=true

[Install]
WantedBy=timers.target
wiki-backup.service

When the wiki-backup timer fires, then the service is invoked. The service runs a script located in /sbin. 

$ cat /etc/systemd/system/wiki-backup.service

[Unit]
Description=Run the backup service once a day
Documentation=...

[Service]
Type=oneshot
User=root
ExecStart=/sbin/wiki-backup
wiki-backup script
$ cat /sbin/wiki-backup

#!/usr/bin/env bash

# Systemd adds random paths at times. Take full control of PATH.
PATH=/bin:/sbin:/usr/bin:/usr/sbin
export PATH

# Read the backup password from conf or ini Failed
wiki_password=...

# Fix the wiki tables just in case. This step produces a lot of noise,
# so send stdout to /dev/null.
if MYSQL_PWD="${wiki_password}" \
   mysqlcheck my_wiki --auto-repair --user=mwuser 1>/dev/null;
then
    echo "Repair wiki database ok"
else
    echo "Failed to repair wiki database"
    echo "Continuing anyways"
fi

# Disable the connection from Apache to MySQL for the dump
if ! systemctl stop apache2.service ;
then
    echo "Failed to stop Apache service"
    echo "Continuing anyways"
fi

# Lock option choice due to MySQL change at versions 5.7.41 and 8.0.32 in
# February 2023. See https://bugs.mysql.com/bug.php?id=109685 and
# https://bugs.launchpad.net/ubuntu/+source/mysql-5.7/+bug/2003866.
if mysql --version 2>&1 | grep -q -E 'mysql[[:space:]]+Ver 8\.0\.32'; then
   echo "Using MySQL --lock-tables --add-locks options"
   mysql_lock_opt="--lock-tables --add-locks"
else
   echo "Using MySQL --single-transaction option"
   mysql_lock_opt="--single-transaction"
fi

if MYSQL_PWD="${wiki_password}" \
   mysqldump --no-tablespaces \
     ${mysql_lock_opt} \
     --events --triggers --routines \
     --add-drop-table --create-options \
     --extended-insert \
     --default-character-set=utf8 \
     -u mwuser -h localhost my_wiki | gzip -q -v9 > /backup/wiki-backup.sql.gz ;
then
    echo "Dump wiki database ok"
else
    echo "Failed to dump wiki database"
    echo "Continuing anyways"
fi

# Re-enable connection from Apache to MySQL for the dump
if ! systemctl start apache2.service ;
then
    echo "Failed to start Apache service"
    echo "Continuing anyways"
fi

exit 0

Tabelle

Some of the tables dumped have different degrees of temporariness. So to save disk space (beyond just gziping), although those tables need to be present in a proper dump, their data does not. However, under certain circumstances the disadvantage of having to rebuild all this data may outweigh saving disk space (for example, on a large wiki where restoration speed is paramount).

See mailing list thread mysql5 binary schema about the topic.

Conversione da Latin-1 a UTF-8

See the relevant section of the upgrading page for information about this process. Also see the talk page for more information about working with character sets in general.

PostgreSQL

You can use the pg_dump tool to back up a MediaWiki PostgreSQL database. For example: 

pg_dump mywiki > mywikidump.sql

will dump the mywiki database to mywikidump.sql.

To restore the dump: 

psql mywiki -f mywikidump.sql

You may also want to dump the global information, e.g. the database users: 

pg_dumpall --globals > postgres_globals.sql

SQLite

If your wiki is currently offline, its database can be backed up by simply copying the database file. Otherwise, you should use a maintenance script: php maintenance/SqliteMaintenance.php --backup-to <backup file name>, which will make sure that operation is atomic and there are no inconsistencies. If your database is not really huge and server is not under heavy load, users editing the wiki will notice nothing but a short lag. Users who are just reading will not notice anything in any case.

phpMyAdmin

Turn your wiki to read only by adding $wgReadOnly = 'Site Maintenance'; to LocalSettings.php.

Find the wiki database in LocalSettings.php. Here is an example of what this looks like in LocalSettings.php: 

## Database settings
$wgDBtype           = "mysql";
$wgDBserver         = "localhost";
$wgDBname           = "sashtmax_mw19999";
$wgDBuser           = "sashtmax_mw19999";
$wgDBpassword       = "S7[88p]jJJ";
  1. Open the browser to your phpadmin link, login, choose the wiki database.
  2. Select Export. Make sure all items under Export are highlighted, and make sure Structure is highlighted (it's important to maintain the table structure). Optionally check Add DROP TABLE to delete existing references when importing. Make sure Data is checked.
  3. Select zipped.
  4. Click on GO and save the backup file.[1]
  5. Remove $wgReadOnly = 'Site Maintenance'; from LocalSettings.php

Remember to also backup the file system components of the wiki that might be required, e.g. images, logo, and extensions.

Collegamenti esterni

HeidiSQL (alternative to phpMyAdmin)

HeidiSQL is similar to phpMyAdmin, but without any restrictions of phpMyAdmin's free version. HeidiSQL requires a direct database connection, where some hosts may only offer web interfaces (phpMyAdmin) to firewalled databases.

Filesystem

MediaWiki stores other components of the wiki in the file system.

The most important of these are:

  • LocalSettings.php
  • uploaded files in the images/ directory (including deleted files, thumbnails, and rendered math and SVG images, if applicable).

The best method to back these up is to place them into an archive file, such as a .tar file, which can then be compressed if desired. On Windows, applications such as WinZip or 7-zip can be used.

For Linux variants, assuming the wiki is stored in /srv/www/htdocs/wiki 

tar zcvhf wikidata.tgz /srv/www/htdocs/wiki

It should be possible to backup the entire "wiki" folder in "htdocs" if using XAMPP.

Configuration files

LocalSettings.php is the most important of these, but a wiki might also have things like .htaccess or other web server configuration files that should be backed up.

Uploaded files

Files uploaded to the wiki are by default put into the images/ directory, separated into subdirectories such as images/8/8f. There are also other directories such as images/archive/ and images/deleted/. These should all be backed up.

The images/thumb/ can be backed up along with everything else, but can optionally be excluded in order to save backup space. This directory stores the derived thumbnails of images and other files; generally multiple thumbnails per wiki file. After restoring from backup, these thumbnails will be recreated as required (although depending on $wgGenerateThumbnailOnParse this may need to be a manual process).

Backup del contenuto del wiki (dump XML)

It is also a good idea to create an XML dump in addition to the database dump. XML dumps contain the content of the wiki (wiki pages with all their revisions), without the site-related data (they do not contain user accounts, image metadata, logs, etc).[2]

XML dumps are less likely to cause problems with character encoding, as a means of transferring large amounts of content quickly, and can easily be used by third party tools, which makes XML dumps a good fallback should your main database dump become unusable.

To create an XML dump, use the command-line tool dumpBackup.php , located in the maintenance directory of your MediaWiki installation. See Manual:dumpBackup.php for more details.

You can also create an XML dump for a specific set of pages online, using Special:Export, although attempting to dump large quantities of pages through this interface will usually time out.

To import an XML dump into a wiki, use the command-line tool importDump.php . For a small set of pages, you can also use the Special:Import page via your browser (by default, this is restricted to the sysop group).

See Manual:Importing XML dumps for more information.

Accesso al server senza shell

See m:Data dumps about Wikimedia database dumps.

WikiTeam3

If you have no server shell access, use Save the Web Project's WikiTeam3 Python 3 script, (full instructions are at that link).

Windows: When using --images, because NTFS does not allow characters such as :*?"<>| in filenames, some files may not be downloaded, please check the errors.log file.
Example usage
  • --curonly dumps only the latest revision of pages
  • --xml exports an XML dump, uses Special:Export by default when no other xmldump method is specified.
  • --xmlrevisions uses API:Allrevisions (MediaWiki 1.27+) xmldump method. Recommended as it's quicker and puts almost no pressure on the MediaWiki backend compared to Special:Export.
  • --images generates an image dump
  • --force generates a dump even if there is one already at Internet Archive
Public wikis
wikiteam3dumpgenerator <WIKI_URL> --xml --xmlrevisions
Private wikis
To dump a private wiki you will have to use a login that has at least read permission on the wiki.
wikiteam3dumpgenerator <WIKI_URL> --xml --xmlrevisions --force --user <USER> --pass <PASSWORD>
If that doesn't work. Login with a web browser, save the site cookies in Netscape format to cookies.txt, and add option --cookies cookies.txt

Scripts

With server shell access

Attenzione Attenzione: Use these at your own risk. Check your wiki's LocalSettings.php for the correct character set to use, as you may need to edit the script to suit.

Shell script - last updated 2012.

  • Another backup script that: dumps DB, files (just pictures by default, option to include all files in installation), and XML; puts the site into read-only mode; timestamps backups; and reads the charset from LocalSettings.

Script does not need to be modified for each site to be backed up. Does not (yet) rotate old backups. Usage: backup.sh -d backup/directory -w installation/directory. Also provides a script to restore a backup restore.sh -a backup/directory/dated_archive.tar.gz -w installation/directory. Shell script - last updated 2013.

Shell script - last updated 2015.

Shell script - last updated 2016.

  • Script to make periodical backups mw_backup. This script will make daily, weekly and monthly backups of your database and images directory when run as a daily cron job.

PHP script - last updated 2017.

  • Another unofficial MediaWiki backup script for Windows by Lanthanis that: exports the pages of specified namespaces as an XML file; dumps specified database tables; and adds further specified folders and files to a ZIP backup file.

Can be used with Windows task scheduler. Last updated 2019.

Without server shell access

For example your wiki is in a wikifarm , using the MediaWiki API .

  • WikiTeam's dumpgenerator Python 2 script can generate an XML dump and an image dump - last updated 2023.
  • Mediawiki Client Tools' MediaWiki Dump Generator dumpgenerator Python 3 script can generate an XML dump and an image dump - last updated 2023.
  • See above: Save the Web Project's WikiTeam3 wikiteam3dumpgenerator Python 3 script can generate an XML dump and an image dump - actively maintained in 2024.

Extensions

Vedi anche

Riferimenti

  1. ↑ Manual talk:Backing up a wiki#Ubuntu 10.10 - Step by Step Instructions
  2. ↑ XML dumps are independent of the database structure, and can be imported into future (and even past) versions of MediaWiki.
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