The Practice of System and Network Administration, Second Edition

Chapter 25. Data Storage

The systems we manage store information. The capacity for computers to store information has doubled every year or two. The first home computers could store 120 kilobytes on a floppy disk. Now petabytes—millions of millions of kilobytes—are commonly bandied about. Every evolutionary jump in capacity has required a radical shift in techniques to manage the data.

You need to know two things about storage. The first is that it keeps getting cheaper—unbelievably so. The second is that it keeps getting more expensive—unbelievably so.

This paradox will become very clear to you after you have been involved in data storage for even a short time. The price of an individual disk keeps getting lower. The price per megabyte has ...