However, the storage industry offers a number of options when it comes to external storage, from electronic storage media, also known as flash memory devices, to external and portable hard disk drives, and even optical media. Each of these storage mediums has its own properties, which make it ideal for different scenarios. Understanding the pros and cons of different external storage types can help both businesses and consumers to make an informed data storage decision.
Electronic storage media, also known as flash memory, includes technologies such as USB thumb drives, SD memory cards and Solid State Drives (SSD). All of these media use electronic methods for data storage and thus contain no moving parts. This makes them resistant to shock and relatively rugged, ideal for mobility. Electronic media is also not affected by magnetic fields, which can corrupt data on traditional hard drives. In addition, access to data is quicker because there is no mechanical head that needs to search for the right files. As soon as these devices are plugged in, their storage is available and the faster read speeds make them highly convenient for many applications.
USB thumb drives are perfect for moving files around and sharing them, because they are portable, low cost and convenient. SD cards are mainly used as storage media for mobile devices such as smartphones, tablets and digital cameras. SSDs can be used as internal storage in notebooks, which offers benefits such as extended battery life and shock resistance.
One of the biggest downsides of flash memory is that all forms of this technology carry a higher cost per gigabyte of storage compared to other media. All flash media also has a limited number of write cycles, which means that after a certain number of usages, the drive or memory card will fail. Data deterioration over time is also a factor - if these drives are left for a number of years there is a chance that data may have become corrupted in random segments, which makes the entire drive unreadable. In addition, data retrieval is difficult on electronic media, so once data is lost or corrupt it is almost impossible to retrieve.
For these reasons, flash memory is not ideal for long-term storage and is more appropriate for short-term applications. Further to this, flash media like USB thumb drives are so portable that they are often forgotten, lost or left in inappropriate places. This makes them a poor choice for the storage of confidential data.
Hard disk drives are the traditional storage medium in notebooks and personal computers. They are also available as external hard drives, which require AC power, and portable hard drives which are powered by USB. External drives provide the benefit of additional capacity whilst portable external drives are geared for users on the move that also require additional capacity. The biggest benefit of these drives is the lower cost per gigabyte relative to other storage media, as well as the large capacities available. External hard drives are now commonly available in capacities of up to 6TB and portable hard drives offer up to 2TB at an affordable price for most users.
The downside to hard drives is the mechanical nature of data storage and access. The read and write head has to physically move across the drive's platter in order to store or access information, which has a number of implications.
Firstly it is slower than flash memory because the drive head must seek the information required. Secondly, the motor inside the drive must run almost continuously, even when the drive is idling, which uses significantly more energy than flash storage. Finally these drives carry a significant amount of risk. Dropping them while the motor is spinning or the drive head is moving can cause data loss and corruption, and strong magnetic fields can erase information. In addition, they are an easy sell for thieves and tend to be a popular target during burglaries, which could also result in data loss. Hard drives are therefore best used for general data storage and backup in the medium-term.
Optical storage media includes Compact Disk (CD), Digital Video Disk (DVD) and Blu-ray disks. This form of storage media is shock and magnetic field resistant, highly reliable as it does not deteriorate over time, and with durability that exceeds both magnetic (hard-drive) and flash memory. In addition, it is a greener solution, as it does not require electricity while storing the data, and a special environment or conditions are not required for storage, beyond keeping the disk in a case or sleeve.
The downsides of this media are that it takes time to burn a disk, which is inconvenient compared to other media, and storage capacities per disk are smaller. While flash drives offer up to 1TB of capacity, the largest optical disk, a BD-R double layer (BD-R DL) disk, is available in capacities of only 50GB. In addition, the majority of optical media is write-only and cannot be reused, so once a disk is burned the content will remain.
While flash storage has therefore replaced optical for everyday data sharing, optical media is the ideal solution for data archiving and backup. Optical media is durable and reliable, and data stored on the disks will not be corrupted or deteriorate over time. Archival quality disks ensure that data is stored and protected for many years.
In addition, new technology advancements have made this storage media even more applicable as a replacement for the traditional magnetic tape storage. Newer disks in capacities of 100GB utilise laser engraving into a new form of optical disk media, which offers an incredibly durable and rugged storage solution with undamaged and uncorrupted data storage for periods of up to 100 years. This makes optical media perfect for long-term storage and archiving requirements.
Ultimately there is no one storage medium that will meet all data storage requirements, and it is therefore advisable to use a combination of flash, hard drive and optical storage for the relevant applications. This can form part of an overall data loss prevention strategy, which is critical to business continuity. Best practice dictates that three copies of files should be kept on at least two different media, with one copy stored offsite. The primary copy may be stored on a computer's hard drive, with two backups, one on another hard drive and one on optical media, can be stored elsewhere for effective backup and recovery ability. The right combination of storage can help protect both businesses and individuals from the consequences of data loss.
