The summary.
MOST IT PROBLEMS ARE NOT TECHNICAL FAILURES
They are process and communication failures. The technical layer is only part of the field.
UNDERSTAND THE LAYERS
Hardware, firmware, operating system, applications. Identifying which layer a symptom belongs to directs the entire diagnosis.
Drivers run with high privilege, which is why many crashes trace to them rather than to applications.
THE QUESTION THAT ELIMINATES MOST POSSIBILITIES
Does this affect one client, all clients, or the server?
TWO UNIT DISTINCTIONS THAT EXPLAIN COMMON COMPLAINTS
Network speed is quoted in bits, while file sizes are in bytes — roughly an eighth of the figure.
Drive capacity is counted differently by manufacturers and operating systems, which is why a drive appears smaller than advertised.
ALL DATA IS NUMBERS INTERPRETED BY CONVENTION
Which is why a file opened with the wrong convention produces nonsense, and why encoding mismatches garble text.
WHEN JOINING ANY ENVIRONMENT
Establish what exists, who administers it, what depends on what, and where it is documented.
Build your own notes from the first day.
