Developing the skill.
WHAT TO PRACTISE ON
A machine you can destroy.
WHAT THAT MEANS PRACTICALLY
A cheap virtual server, or a virtual machine on your own computer.
WHY NOT A PRODUCTION SERVER
Learning involves breaking things.
WHAT TO LEARN FIRST
Navigation and file handling Permissions Reading logs Managing services Package management
WHY PERMISSIONS EARLY
A large proportion of real problems are permission problems.
WHAT TO PRACTISE DELIBERATELY
Breaking a service and diagnosing it Filling a disk and clearing it Restoring from a backup Recovering a machine you locked yourself out of
WHY THE LAST ONE
It will happen, and the first time should not be on a live server.
WHAT TO BUILD
A small server that does something real: a site, a monitoring tool, a backup destination.
WHY REAL
Tutorials teach commands; running something teaches operation.
WHAT TO READ
The manual pages of commands you use.
WHAT TO AVOID
Memorising commands without understanding Copying solutions without reading them Working only as root
WHAT SEPARATES COMPETENCE
Diagnosing methodically rather than trying things.
WHAT TO DEVELOP
The habit of asking what the evidence actually shows.
