Nice tutorial. I do performance work and the only tools really necessary as I found are sar, ps, and munging thorugh /proc for nfs data.
At a company I did a study to prove to a customer how light weight sar was and stated it was the cost of one particular heavy weight transaction. The person who was not a fan said “ha”. I said one transaction across 100 servers for the entire day, how many transactions do we do now in a day (tens of millions) ….
shoot and score!
Great write up and examples dude!