I work as System Specialist. During my work I often came to point that normal kernel from distribution doesn't work. Whole or part of server was unusable because one of these common reasons:
- Virtualization support with combination of new HW
- Missing driver for some Raid Controllers
- Missing driver for network cards
- Security hardening patches for specific systems
I don't remember which of the reason was the first when I must build my own kernel to be able use server or computer with all it's hardware. In few next years another big reason appear.
- New kernel have fixed some performance issues
Now we can talk about how to do it.