> What is the difference between 'DevOps' and a system administrator?
That "DevOps" is supposed to be so easy that an ordinary full-stack developer can pick it up and there is no need for expensive senior system administrators and especially DBAs (="the cloud will handle it for us").
True: when one relies on cloud-provided databases (Amazon RDS), the need for a DBA goes down a bit, especially with a decent support contract from the cloud provider.
But the other part, like how to configure a machine for maximum throughput, how to properly implement failover networking, how to do OS upgrades (and especially with Docker containers, how to keep the stuff in the images updated!) and most importantly how to write a Docker image that does not "just work" but is performant, upgradeable and doesn't place stuff around everywhere totally ignoring LSB... this needs Linux administration experience.
tl;dr: companies label it "devops" to save money for Linux/DB Admins, but this gamble can really fuck up when you suddenly do need the skillset of a real admin.