I have a private ownCloud server that currently stores its data in the default
/var/www/owncloud/data directory, which ordinarily takes up storage space on the server filesystem itself.
Thankfully, ownCloud supports connecting to external storage services in order to extend the amount of space available to the user. In my case, I used Amazon S3 buckets — which offer cost-effective and reliable object storage — as targets that ownCloud was able to connect to and mount as directories within the application and file system itself. This a great option for storing data that needs to scale in a quasi-archival manner versus warmer (hot) data that’s updated and synced daily.
Best of all, buckets can be added and removed without issue (read: unmounted and mounted), which means that they are entirely portable if I decide to change hosting providers for my ownCloud server itself. This should also work for anyone who uses NextCloud, as it’s a fork of ownCloud and thus the integrations are similar.