A DBA managing a highly available database server is charged with a huge responsibility. The amount of integration, speed of operations, and urgency behind resolving performance degradation can be extremely stressful. Some personalities thrive under this kind of pressure, while others will find it impossible to concentrate and will become paralyzed in fear.

We're not going to claim that every DBA in this position is a battle-weary veteran, typing furiously to save the day while disaster looms. This kind of scenario only exists in movies and often leads to compounding the original problem. In reality, a DBA's job includes many more calculated reactions even when managing a transaction-heavy database with frightfully low tolerance for downtime. The best tip we can give and the whole reason behind this book is to have an expansive bag of tricks.

For the purposes of this chapter, our bag is full of common Linux utilities useful for troubleshooting. With them, we approach system malfunctions...