Encuesta sobre la V Convención de la AFE

Computer systems have become modular over the last few years, and one of the benefits is removable media. Removable media refers to any type of storage device (such as a floppy drive, magnetic tape cartridge, or CD-ROM) that can be removed from the system. Disk drives that once cost thousands of dollars now cost hundreds or even less. What once took up a whole room can easily be put in a coat pocket.

It’s important to remember that removable media are subject to viruses, physical damage, and theft. If a CD-ROM is stepped on or scratched, it probably won’t work properly. If it’s stolen, it won’t be available, and the information it contained will be gone forever. That infor- mation could include customer lists, IP addresses, databases, financial spreadsheets or any- thing else of a sensitive nature.

The following sections discuss the most common types of removable media in use today, and the physical and operational measures necessary to safeguard them.

Tape

One of the oldest forms of removable media is magnetic tape. Magnetic tapes come in a variety of types and sizes. Older tapes were reel-to-reel and were bulky and sensitive to environmental factors such as heat and moisture. Newer tapes are cartridge- or cassette-oriented and are smaller and much more durable. Some of the new tape technologies can store on a single tape what once would have required a 10-foot-by-10-foot tape vault. This single tape is slightly larger than a CD-ROM carrying case.

Magnetic tapes have become very fast, and they can hold enormous amounts of data. They’re commonly used to back up systems and archive old data. The major concern with tape involves physical security—a tape is easy to remove from the premises undetected.

Tape can be restored to another system, and all the contents will be available for review and alteration. It’s relatively easy to edit a document, put it back on the tape, and then restore the bogus file back to the original computer system. This of course, creates an integrity issue that may be difficult to detect.

Tapes can also become infected with viruses, and they can infect a system during the data recovery process. Files going onto a tape drive should be scanned to ensure that they’re virus free.

One of the biggest issues when using tape has always been trying to figure out the best way to rotate sets of backups.

You should discover that all of these are valid methods of rotating tape sets in order to maintain multiple copies that can be restored after a disaster. One method isn’t monu- mentally better than another, and you’ll want to identify the one that would work best in your implementation.

While tape used to be the standard for removable media, it is quickly being replaced in the market by newer technologies for backups. You need to know tape for this exam, but for the real world, you should know that it isn’t being deployed at anywhere near the rate it used to be.

CD-R

The CD Recordable (CD-R) is a relatively new technology that allows CDs to be made or burned on a computer system. CD-Rs operate like regular CDs, and they can be burned quickly. Most new computer systems come standard with a CD-R burner or CD-R drive. Data can be quickly backed up to or restored from the CD-R.

CD-Rs are susceptible to computer viruses, and an infected file on the computer that is transferred to the CD-R will infect another system when the file is downloaded. All files should be scanned for viruses before they’re written to or read from a CD-R. Data theft is also easy with a CD-R; an attacker can get on a system that has a CD-R and copy data from hard disks or servers. Some older CD-Rs are susceptible to erasure by sustained exposure to sunlight, so it’s generally a good idea to keep CD-Rs out of environments that are high in ultraviolet (UV) light. Finally, most software products now come on CD, and they can disappear quite easily. This type of theft can cost a company thousands of dollars.

Whether the removable media you use is tape, CD-R, hard drives, or other media, you should bear in mind that one of the biggest vulnerabilities you face is the theft of that media and the data it holds. The best protection you have is keep a close watch over the media; make sure it’s securely and safely locked up when not in use.

Understanding Tape Rotation Schemes

As an administrator, you know the importance of backups and having more than one set of data available to restore. In this exercise, you’ll use the Web to research some of the most commonly implemented tape rotation schemes and compare/contrast them.

Using the Web, research these methods of tape rotation and look for the differences between them:

1. Tower of Hanoi

2. Grandfather-Father-Son (GFS)

While the exam focuses on CD-R, you should know that CD-RW (offering the abil- ity to write) has surpassed CD-R, and is now being eclipsed by read and write DVD. The enormous storage capacity of DVD/DVD-R, and ease of use, is quickly making it a favorite when it comes to holding large amounts of important data. A single-layer DVD can store approximately seven times what a CD can (4.7 GB), which makes it much more convenient for large backups, and archives.