We come to building security by continuing out to the next ring. All the protection inside the server won't do us any good if the server decides to take a walk at three in the morning. Just as we secure the inside of the server, we need to secure the outside too.
Firstly, where is the server located? Is it in a common area where anyone in the office could get to it? This could be bad on a number of levels, the first being that someone could accidentally or on purpose cut power to it. We can mitigate external power outages to some extent by installing battery backup units and such, but someone with physical access to the machine can easily get around that and cut power to our servers. To its credit, MariaDB—when we use a transactional or crash safe storage engine—guards against losing or corrupting data in such cases, but at the very least, a surprise power outage will disrupt every application that needs to talk to that database server. If the server is in a locked room...