Well, it's ultimately files on a disk, as well as queryable data. So probalby pretty easily.

Logical database backups (I'd point to mysqldump/mydumper & myloader if we were talking about mysql), combined with physical snapshots & copies of the binary files.

500 GiB is a lot, but not too out there these days.

It's typically being backed-up by way of whatever hypervisor running snapshots of the VM.

Longer term, we are looking at synchronous log replication so that no business data would ever be lost on a primary outage. Having an availability problem is acceptable as long as we can bring everything back up in a reasonable amount of time.