Upgrading to ArangoDB 3.2
Please read the following sections if you upgrade from a previous version to ArangoDB 3.2. Also, please, be sure that you have checked the list of incompatible changes in 3.2 before upgrading.
Switching the storage engine
In order to use a different storage engine with an existing data directory, it is required to first create a logical backup of the data using arangodump. That backup should be created before the upgrade to 3.2.
After that, the ArangoDB installation can be upgraded and stopped. The server should then be restarted with the desired storage engine selected (this can be done by setting the option --server.storage-engine) and using a non-existing data directory. This will start the server with the selected storage engine but with no data.
When the server is up and running, the data from the logical backup can be re-imported using arangorestore.