Site backup

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Note: You are currently viewing documentation for Moodle 2.9. Up-to-date documentation for the latest stable version of Moodle may be available here: Site backup.

Site backups are recommended in order to have all data saved with the best confidence and the shortest recovery time.

What needs to be backed up?

A Moodle system comprises three parts:

  1. The data stored in the database (For example, a MySQL database)
  2. The uploaded files (For example, site and course files uploaded via Moodle located in moodledata)
  3. The Moodle code (For example, everything in server/htdocs/moodle)

You can confirm where all these things are located in a Moodle installation by checking the config.php file.

  1. $CFG->dbna shows the database name
  2. $CFG->prefix shows the the database table name prefix
  3. $CFG->dataroot controls where the uploaded files are stored; and
  4. $CFG->dirroot points to where the code is stored.
Tip: Generally speaking, the database ("dbna and prefix") and the uploaded files (dataroot) are the two most important to copy on a regular basis. These contain information that will change most often. The Moodle code (dirroot) is less important as a frequent backup, since it will only change when the the actual code is changed through upgrades, addins and code tweaks.

Creating a backup of your Moodle site


The right way to back up your database depends on which database system you are using. The instructions below are one way to back up a MySQL database. Another option would be to use a tool like phpMyAdmin to manually make a backup. The documentation for your database will give more options.

There are many ways to do such backups. Here is an outline of a little script you can run on Unix to backup the database (it works well to have such a script run daily via a cron task):

cd /my/backup/directory
mv moodle-database.sql.gz moodle-database-old.sql.gz
mysqldump -h -u myusername --password=mypassword -C -Q -e --create-options mydatabasename > moodle-database.sql
gzip moodle-database.sql

Character encoding

Make sure that a database backup uses the correct character encoding. In most databases, use UTF-8.

When dumping the entire Moodle database, check for possible character encoding issues. In some instances, backups created with mysqldump or phpMyAdmin may not properly encode all of the data. This will result in non-readable characters when the database is restored.

Tip: One solution is to use MySQL Administrator 1.1 or another tool that will force a UTF-8 dump of the data.

Tools for database backups

  • phpMyAdmin is the tool of choice with most web hosting providers.
  • MySQLDumper is a backup script for MySQL databases, written in PHP and Perl. MySQLDumper uses a proprietary technique to avoid execution interruption when running PHP scripts (the max. execution time is usually set to 30 seconds). MySQLDumper also cares for the encoding problems mentioned above. It also works with compressed files.

Data files

They are just files, so all you have to do is make a copy of them somewhere safe. You may then want to compress that copy using zip or gzip.

Since typically, a lot of the files will stay the same, and only a few new ones will be uploaded or edited, you can use a tool like rsync to only copy the changed files, which is more efficient.

Using rsync to backup files

For the files, you can use rsync regularly to copy only the changed files to another host:

rsync -auvtz --delete -e ssh /my/backup/directory/

If you want to run the cronscript at the machine you are running Moodle at you have to use following rsync syntax

rsync -auvtz --delete -e ssh /path/to/local/folder/ remoteuser@remoteserver:/path/to/remote/folder/

If you do not want the root mailbox be spammed by statusmails of the rsync use:

 rsync -autzq --delete -e ssh /path/to/local/folder/ remoteuser@remoteserver:/path/to/remote/folder/

If your Moodle hosting provider does not allow ssh (or just do not provide it) and you have simple ftp access with a username and a password you can also use:

mkdir /tmp/remote-folder
curlftpfs /tmp/remote-folder
rsync -auvtz --delete /tmp/remote-folder /my/local/backup/folder/
umount /tmp/remote-folder
rmdir /tmp/remote-folder

Entire database backup can be accomplished (tested on cPanel web interface) using the following command:

wget --http-user=username --http-password=password

and the entire backup of the Moodle code tree:

wget --http-user=username --http-password=password`date +"%-m-%d-%Y"`.tar.gz

Some customization might be needed for other web interface like (webmin?)

Code files

If you have not customised the code, you can always download a new copy. However, it is still a good idea to keep your own local copy with the rest of your backup, and if you are doing customisation, it is essential. The steps are the same as for backing up the data files.

Restoring a site backup

If you have followed the above instructions and created a backup of a Moodle site, you may need to know how to restore the site backup you created. Here is a set of basic steps that make up the restore process.

1. Rename the original Moodle directory to something different (so you still have it) and copy the backed up Moodle directory or a newly downloaded Moodle directory in its place.

2. If you are running MySQL, a backup of the database should be a .sql, .gz or .tar.gz file. If it is .tar.gz or .gz you need to extract it until it is an sql file.

tar -xzvf moodlesqlfile.tar.gz

3. If you are running mysql, import the SQL file back into a newly created database on the MySQL server. Be careful here, some backups try to import right back into the same working database that Moodle is connected to. This causes database problems that damage a Moodle installation. The best thing to do is make a new database, restore the backed up database into it, and change the Moodle config.php file to connect to this new database (this way you still have the original database).

Once you have created the new database:

mysql -p new_database < moodlesqlfile.sql

For other databases, follow their instructions for restoring a backup.

See also