When the why is clear, the how is easy.
In the previous blog of our tape series, “Tapes as a timeless long-term investment”, we’ve established that magnetic tapes are a game-changer in today’s growing need for data storage and why it’s a better alternative to its competitors. However, maximizing its utility is a power wielded by the user. Let us understand in-depth the working of magnetic tapes.
Tape storage constitutes multiple components integrated to provide a system capable of reading, writing, and storing data. But before we jump into understanding the tape infrastructure as a whole, let us address the primary question:
What Is Tape?
Magnetic tape consists of two main layers stacked together: the base film and the magnetic layer. The base film, also known as the backside of magnetic tape, is a substrate that provides flexibility and strength. Materials such as paper, cellulose acetate, and polyvinyl chloride compose this layer. The magnetic layer or the recording layer lying above the base film is typically made of metallic oxides. Iron oxide, chromium dioxide, etc. to name a few. This layer is where all the magic happens, where data gets stored due to its ability to get magnetized by electric signals.
How Is Data Stored on Tapes?
With the layers and their functionalities established, let’s understand how the data in tapes are stored.
Firstly, we keep in mind that data is essentially just a bunch of zeroes and ones. All data is stored through binary code, through bits. The science involved in storing the data revolves around electromagnetism and ferromagnetism. Electrical signals magnetize the magnetic tape columns to either have a downwards or upwards facing magnetic North Pole, thus differentiating the zeroes and ones. Similarly, the tape columns read can generate a current through induction in different directions resulting in zeroes and ones, thus establishing a secure form of data storage. This mechanism resulted in the need for a read/write head capable of magnetizing the tape leading to the introduction of tape drives.
Tape drives are storage devices that are capable of reading from and writing to magnetic tape. The input for this device is a tape cartridge. The tape cartridge is a spool of magnetic tape comprising data that will be sequentially read. There are two scans involved in tape data storage, helical scan or linear scan. Helical scan has the read/write head touching the tape while linear scan has zero contact between the head and tape. While helical scan offers better data transfer rates, the linear scan is more robust and reliable due to the absence of contact between the various parts of the tape system.
Tape cartridges are not to be confused with tape cassettes. The working of a cassette tape revolves around two spools of tape called the take-up and supply pully contrasting to the one spool used in cartridges. Similar to tape drives used alongside cartridges, cassette tape recorders and players are cassettes counterparts. Cassette storage is primarily used in the audio industry while tape storage is used by research facilities and enterprises to backup data.
Tape Storage System
Having understood how data is stored on tapes, let’s dive into the functioning of a tape storage system in the big picture.
As a whole, backup to tape centers around tape libraries. A tape library, known by many names such as tape silo, jukebox, or tape robot comprises multiple tape drives, slots to hold the tape cartridges, and a robotic system. The robotic system takes the help of an RF scanner or barcode reader to identify the required tape cartridge present in slots and loads them into the respective tape drives. This entire process is how the tape is backed up and used in tape libraries.
Virtual tape libraries, however, use a disk-based backup system that emulates the working of tape libraries. The virtualization of hard disks as tapes enables the user to integrate the data stored with existing backup software. Data is written sequentially, similar to tape storage’s working, but the speed of writing and reading the data is improved as the underlying storage media is disks. However, the cons of using VTLs arise from the downsides of using hard disks as storage media.
A use case of tape libraries is in the context of tape vaults.
Tape vaulting happens offsite, away from the onsite primary infrastructure, and is used to secure and backup data. In this process, data is backed up and vaulted to tapes based on the recovery point objective, an indicator of the minimum amount of data loss that can be tolerated. Tape vaulting is a service that includes the collection of magnetic tapes in vaults, its storage under secure and optimal environmental conditions, and providing insurance to its users. Alongside tape vaulting is tape rotation, which ensures that data stored on the tapes are up to date and offers maintenance of data.
Tape Technology Revolutionized
Having understood the tape landscape, let us address a couple of astounding advancements in tape technology.
LTO’s have revolutionized the tape storage industry. With their ever-increasing storage capacity and reliability, LTOs continue to be a game-changer in data storage. As always, lets first address the elementary question:
What Is an LTO?
Dating far back to the 1990s, Linear Tape Open’s development as an open-format tape storage technology in contrast to its proprietary competitors truly set it apart. The open standards incorporated in the LTO technology ensured that the LTO tape cartridges were compatible with different vendors. It provided its users with numerous options to choose from and hence made it user-friendly.
LTOs are known for their ability to be adaptable, scalable and for their high-density data storage. They offer high performance, reliability, durability and last for over 30 years. Over the years, as the LTOs introduced newer generations, to provide their customers with insurance and backward compatibility, every new generation introduced could read back two generations and write back one generation. (Applicable up to LTO generation 7)
Let us look at a few statistics that will truly highlight the capacity of LTOs. LTO gen5 offered a storage capacity of up to 1.5TB while the latest LTO gen9 provides an enormous amount of 18TB. This is a tremendous increase in storage capacity that met the market demands across the years. LTO gen9’s features include WORM (write once read many) preventing overwriting of data, multi-layer security support via hardware encryption, and supports LTFS. LTFS (linear tape file system) allows the user to view and access tapes easily, with a simple drag and drop technology. Linear LTO gen10 is likely to offer 36TB, a 50% increase from its previous generation. This proves that LTOs evolve continuously to provide more capacity at lower rates.
The various elements and their integration together to constitute the entire tape landscape is understood. However, tagging alongside this is the question:
How Much Would We Be Investing? Is It Going to Be Worth the Price?
To answer these questions, let’s have the numbers speak for themselves. The cost of tape libraries ranges from around 11 thousand dollars to a 110 thousand dollars or even a million dollars. The amount of money spent is dependent on various factors such as the size of the tape library, the number of tape drives, slots, and the cartridges it can support. The increase in complexity and capacity results in a proportional increase in the price. Further, tape libraries are capable of expansion, resulting in a reliable and scalable tape infrastructure. It is essential to understand that these tape libraries have an expensive upfront cost while cloud storage requires periodic installments. However, the type of data stored influences the decision of which storage means to use.
The cold storage data costs about half a rupee or more per gigabyte in cloud storage. This amount is small when compared to a rupee and a half the user would pay in the case of tape libraries, but time is an influential factor. As the name suggests, cold storage is data that is to be preserved for a decade or more. Hence, over the years, cloud storage whose pricing is subject to market value would be a gamble and an expensive alternative to the slightly heavy upfront cost invested in tape libraries.
The below scenario draws a clearer picture.
|Tape Library||Cloud Storage|
|Capacity: 36 TBTime Period: 15 Years (180 months)Tape Drive: LTO Half height fiber channel drive (12 TB, Qty: 3)Estimated Cost: $17,500 ~ Rs 13,05,000||Capacity: 36 TBTime Period: 15 Years (180 months)Cost per Gigabyte: $0.004Estimated Cost: $26,000 ~ Rs 19,80,000|
Hence, taking into account the time duration and the data to be stored, tape libraries are truly a better alternative to cloud storage or hard disks.
Zmanda, the New Superpower
With a strong foundation of tape and its working, our next step in procuring tape is to find the apt service. Zmanda is the unanimous option. We provide you with unique features that aren’t available in the market. With a pay as you go service similar to that of cloud storage, unique multi-tiered backup that utilizes various tape storage media, and a perfect integration with our Zmanda Management Console (ZMC) to provide top notch user experience, our product truly takes the lead. We also provide tape vaulting features to store tapes containing priceless data, also known as legacy tapes. We ensure to use the latest and the most compatible version of LTOs to give you the easiest yet safest tape backup storage systems.
We have technical experts who have gained mastery in tapes over the past 20 years to help you through every step of the way. Our product is tailor made specifically to meet all your backup requirements and to provide the best solution for your data. Your data is our priority. Click here to find out more of Zmanda’s features and book yourself a free trial.