Tape DrivesStill the Preferred Media for Data Backups

by : Jamie Wallis

Hard disks are very reliable machines that are installed as the primary data storage media in all computers. This is because they are the only storage devices that have a huge capacity and, yet, offer random access. In other words, the computer can instantly pick up data residing in any corner of the hard disk. This combination of huge capacity, random access and the capability to allow write and rewrite operations millions of times makes hard disks unbeatable as the primary storage media of choice for computers. Despite all their features, however, hard disks are still machines invented by humans. They have a fixed life span after which there is a danger that they may go down anytime. This period is typically anywhere between three to five years. If a hard disk crashed due to any number of reasons – hardware or software errors or natural or man-made disasters – it can be catastrophic. All the data that you have stored on the disk can instantly become inaccessible and out of bounds. Total data loss causes many companies to fail each year as they cannot cope with the consequences – they lose access to all their records and information and there are massive financial losses. Therefore, the importance of taking regular data backups just cannot be over-emphasised. A variety of data backup media exist in the market, such as CDs, DVDs, USB drives and portable hard disks. However, the media that remains the most popular and effective for taking backups by companies is the tape drives. Just like hard drives rule in the world of primary storage for computers, tape drives rule the data archive market. What are tape drives actually? Simply put, a tape drive consists of a large length of tape that is coated with a magnetic material, much like the platters of a hard disk carry a magnetic coating. This tape is wound around a couple of spools and the entire thing is enclosed in a plastic cartridge. The tape drive has a read / write head that is stationary and remains fixed at one place. Unlike in a hard drive where the spindles rotate at the same place while the read / write head moves all over, in a tape drive it is the tape that has to move back and forth in front of the stationary head so that it can access data for writing, rewriting and deleting or saving. This kind of data access is called “sequential access" as the data can be only read strictly in sequence. Tape drives use old technology of recording data, exactly like audio or video cassettes of yore. However, they are still quite popular and remain the best option for archiving a huge amount of important data. There are many reasons for this. For one, tape cartridges are quite cheap and easily available. No other data storage media can match the cost they offer in terms of per MB of storage. The sequential data access has its benefits, even though the entire tape has to move back and forth before you can access a particular file. If a part of the tape gets corrupted, the entire data is not affected. You just have to cut that exact portion of tape, glue the ends together and you have the tape running again, offering you access to the rest of the data. Another benefit is that the tape cartridge that stores the data exists separately from the tape drive. In a hard disk, since the data-holding platters are built into the drive, any power surge can wipe out all the data. A tape cartridge on the other hand has no parts through which electricity flows. In case of a lightning strike or power spike, only the tape drive is damaged, while the tape cartridge that stores the data remains safe and intact. It is easy to take a lot of tapes and store them in a safe place away from the computers. They are quite small and can be easily transported. Data backup media has advanced in the last few years and has made rapid strides in terms of storage space. HoweverFree Articles, nothing can still come close to tape drives for the combination they offer of reliability and low cost for archiving a large amount of data for a long time.