Restoring backup

To restore a Nextcloud installation there are four main things you need to restore:

  1. The configuration directory

  2. The data directory

  3. The database

  4. The theme directory

Note

You must have both the database and data directory. You cannot complete restoration unless you have both of these.

Restore folders

Note

This guide assumes that your previous backup is called “nextcloud-dirbkp”

Simply copy your configuration and data folder (or even your whole Nextcloud install and data folder) to your Nextcloud environment. You could use this command:

rsync -Aax nextcloud-dirbkp/ nextcloud/

Restore database

Warning

Before restoring a backup you need to make sure to delete all existing database tables.

The easiest way to do this is to drop and recreate the database. SQLite does this automatically.

MySQL

MySQL is the recommended database engine. To restore MySQL:

mysql -h [server] -u [username] -p[password] -e "DROP DATABASE nextcloud"
mysql -h [server] -u [username] -p[password] -e "CREATE DATABASE nextcloud"

If you use UTF8 with multibyte support (e.g. for emojis in filenames), use:

mysql -h [server] -u [username] -p[password] -e "DROP DATABASE nextcloud"
mysql -h [server] -u [username] -p[password] -e "CREATE DATABASE nextcloud CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci"

PostgreSQL

PGPASSWORD="password" psql -h [server] -U [username] -d template1 -c "DROP DATABASE \"nextcloud\";"
PGPASSWORD="password" psql -h [server] -U [username] -d template1 -c "CREATE DATABASE \"nextcloud\";"

Restoring

Note

This guide assumes that your previous backup is called “nextcloud-sqlbkp.bak”

MySQL

MySQL is the recommended database engine. To restore MySQL:

mysql -h [server] -u [username] -p[password] [db_name] < nextcloud-sqlbkp.bak

SQLite

rm data/owncloud.db
sqlite3 data/owncloud.db < nextcloud-sqlbkp.bak

PostgreSQL

PGPASSWORD="password" psql -h [server] -U [username] -d nextcloud -f nextcloud-sqlbkp.bak

Synchronising with clients after data recovery

By default the Nextcloud server is considered the authoritative source for the data. If the data on the server and the client differs clients will default to fetching the data from the server.

If the recovered backup is outdated the state of the clients may be more up to date than the state of the server. In this case also make sure to run the maintenance:data-fingerprint command afterwards. It changes the logic of the synchronisation algorithm to try an recover as much data as possible. Files missing on the server are therefore recovered from the clients and in case of different content the users will be asked.

Note

The usage of maintenance:data-fingerprint can cause conflict dialogues and difficulties deleting files on the client. Therefore it’s only recommended to prevent dataloss if the backup was outdated.

If you are running multiple application servers you will need to make sure the config files are synced between them so that the updated data-fingerprint is applied on all instances.