par exemple, passer de sqlite à mysql
https://github.com/owncloud/core/issues/9526
en ligne de commande se placer dans le répertoire d'owncloud
php ./occ db:convert-type –password=“<password>” –all-apps mysql <mysql_user> localhost <mysql_db>

https://software.opensuse.org/download/package?project=isv:ownCloud:desktop&package=owncloud-client
wget http://download.opensuse.org/repositories/isv:ownCloud:desktop/xUbuntu_14.04/Release.key
apt-key add - < Release.key
echo 'deb http://download.opensuse.org/repositories/isv:/ownCloud:/desktop/xUbuntu_14.04/ /' » /etc/apt/sources.list.d/owncloud-client.list
apt-get update
apt-get install owncloud-client

comme owncloud a été retiré des dépots (pour non maintenance), on peut l'installer à partir d'ici :
→ http://software.opensuse.org/download/package?project=isv:ownCloud:community&package=owncloud
echo 'deb http://download.opensuse.org/repositories/isv:/ownCloud:/community/xUbuntu_14.10/ /' » /etc/apt/sources.list.d/owncloud.list
wget http://download.opensuse.org/repositories/isv:ownCloud:community/xUbuntu_14.10/Release.key
sudo apt-key add - < Release.key
rm Release.key
apt-get update
apt-get install owncloud

impossible to write to binary log since BINLOG_FORMAT = STATEMENT
→ https://github.com/owncloud/core/issues/16008#issuecomment-98539419
vim /etc/mysql/my.cnf
et ajouter binlog-format = MIXED juste après les autres instructions binlog
service mysql restart