Network+ Certification (Outline) - Chapter 16: Network maintenance

Chapter summary: Magnetic tape is the most popular storage medium for backups; backup software enables you to select the data you want to back up and sends it to the device you use for backups; daily backup jobs can be full backups, incremental backups, or differential backups;...
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Network+ Certification (Outline) - Chapter 16: Network maintenance Chapter 16, Network Maintenance|1| Chapter Overview A. Backups B. Antivirus Policies C. Patches and Updates Chapter 16, Lesson 1 Backups|2| 1. What Is a Backup? A. Backups are copies of data that you make on a regular basis. 1. If a storage device fails or is damaged and the data stored there is lost, you can restore it from a backup in a timely manner. B. Even if you have other storage technologies in place that provide fault tolerance, such as mirrored disks or a redundant array of independent disks (RAID), you still need a backup solution. C. Networks both complicate and simplify the process of making regular backups. 1. The process is more complicated because you have data stored on multiple devices that must be protected. 2. The process is simpler because you can use the network to access those devices. D. A network backup strategy specifies what data you back up, how often you back it up, and what medium you use to store the backups. E. The backup hardware, software, and administrative policies you will use depend on 1. How much data you have to back up 2. How much time you have to back it up 3. How much protection you want to provide 2. Backup Hardware|3| A. Selecting a backup drive 1. You can use any type of storage device for backups. 2. Try to automate as much of the backup process as possible. 3. Select a device that can store all of your data without frequent media changes. a. You do not need a drive that can hold all of the data stored on all of your network’s computers. b. Be selective about which data you want to back up. (1) Determine how much data needs to be protected before you decide on the capacity of your backup device. 4. Consider the speed at which the drive writes data to the medium. 5. Backup jobs typically run during periods when the network is not otherwise in use so that all of the data on the network is available for backup. a. The amount of time that you have to perform your backups is sometimes called the backup window. 6. The backup device that you choose should depend in part on a. The amount of data you must protect b. The amount of time that you have to back it up c. Examples (1) If you have 10 GB of data to back up and your company closes down from 5:00 P.M. until 9:00 A.M., you have a 16-hour backup window—plenty of time to copy your data, using a medium-speed backup device. (2) If your company operates three shifts and only leaves you one hour, from 7:00 A.M. to 8:00 A.M., to back up 100 GB of data, you must use a much faster device or several devices.|4| 7. Cost is always a factor in selecting a hardware product. a. Faster drives are generally more expensive. b. A low-end backup drive can cost $100 to $200, which is suitable for backing up a home computer where speed is not a major factor. c. When you move up to the drives that have the speed and capacity that make them suitable for network backups, the prices increase exponentially. d. High-end backup drives can have prices that run into five figures. e. When you evaluate backup devices, be aware of the product’s media costs as well. f. Backup devices nearly always use a removable medium, such as a tape or disk cartridge, which you must buy along with the drive. g. At first, some products might seem to be economical because the drive is inexpensive, but in the long run they might not be because the media are so expensive. h. One of the most common methods of evaluating various backup devices is to determine the cost per megabyte of the storage that a device provides. (1) Divide the price of the medium by the number of megabytes it can store, and use this figure to compare the relative cost of various devices.|5| B. Selecting a drive interface 1. Backup devices can use any of the standard computer interfaces: a. IDE b. Universal serial bus (USB) c. SCSI d. Some backup drives connect to the computer’s parallel port, although this type of connection is just a form of SCSI that uses a different port. 2. The most common interface used in high-end network backup solutions is SCSI.2 Outline, Chapter 16 Network+ Certification, Second Edition a. SCSI ...