In order to make an informed decision, it is important that companies have an understanding of the technology and exactly what it does. This may seem an obvious statement until we consider that many staff within an organisation do not understand the principles of storage, how it operates, what it is for and why they need it. This lack of understanding all too often leads to a simplistic approach of adding expensive primary storage which can often raise more problems that it solves.
Secondary storage utilises tape or optical technology, but could also include elements of NAS or RAID. In very basic terms, secondary storage exists to compliment your primary storage e.g. hard drive. It is usually in the form of removable media, such as tape, MO, DVD or CD, and is commonly situated in an automated environment.
The type of secondary storage used depends heavily on the speed and frequency that the customer needs to access data. The access time is the time it takes to retrieve files and documents from your stored information. Access to data is measured in seconds and speed of access, and the solution you choose will depend on access to the data that you are storing. If files are not used regularly it is possible to store them in a form where access time is slightly longer, whereas vitally important files must be available at the touch of a button.
Each type of secondary storage provides different access times to the data stored. While tape can store very large files, the access time to data is slower, whereas files stored on MO, DVD or CD (i.e. optical technology) can be accessed much more quickly but less information can be stored because the capacity of optical products is lower.
Once we have taken all of these elements into consideration and have a basic understanding of the technology, it is time to enter the final stage of the storage decision-making process which leads us to the big question: Should you choose tape or optical storage technology for your secondary storage requirements?
Tape technology is a tried and tested method of data back-up. It is a removable form of storage offering high capacity. Tape storage has proved itself as a secure and reliable way to store and protect your data effectively, so where is the need for optical? Optical storage is often misunderstood. It is a highly specialised technology offering faster time to data for smaller file sizes. Basically, optical tends to be used for file based access and archiving where standards require the use of WORM media is used for short-term access to files that need to be obtained quickly. When data is used less frequently, it can be moved onto tape, which is more cost effective, and has higher data capacity. Both mediums of storage can be used separately or in conjunction with the other. Most companies have data which ages and goes through ever changing access requirements from creation to archive storage.