Make Your Own Backup System – Part 1: Strategy Before Scripts

Summary

Backup: Beyond the Simple CopyFor as long as I can remember, backup is something that has been underestimated by far too many people. Between flawed techniques, "Schrödinger's backups" (i.e., never tested, thus both valid and invalid at the same time), and conceptual errors about what they are and how they work (RAID is not a backup!), too much data has been lost due to deficiencies in this area.Nowadays, backup is often an afterthought. Many rely entirely on "the cloud" without ever asking how - or if - their data is actually protected. It's a detail many overlook, but even major cloud providers operate on a shared responsibility model. Their terms often clarify that while they secure the infrastructure, the ultimate responsibility for protecting and backing up your data lies with you. By putting everything "in the cloud", on clusters owned by other companies, or on distributed Kubernetes systems, backup seems unnecessary. When I sometimes ask developers or colleagues how they handle backups for all this, they look at me as if I'm speaking an archaic, unknown, and indecipherable language. The thought has simply never crossed their minds. But data is not ephemeral; it must be preserved in every way possible.I've always had a philosophy: data must always be restorable (and as quickly as possible), in an open format (meaning you shouldn't have to buy anything to restore or consult it), and consistent. These points may seem obvious, but they are not.I have encountered various scenarios of data loss:Datacenters destroyed by fire – I had 142 servers there, but they were all restored in just a few hours.Server rooms flooded.Servers destroyed in earthquakes, often due to collapsing walls.Increasing incidents of various ransomware attacks.Intentional damage by entities seeking to create problems.Mistakes made by administrators, which can happen to anyone.The risk escalates for servers connected to the internet, like e-commerce and email servers. Here, not only is data integ...