How Does LTO Tape Do It?

The LTO program gets a variety of inquiries about the technology including “how does the capacity of LTO tape keep increasing so much?” In this BlogBytes we take a deep dive into the technology and compare it to disk by offering an overview of the recent INSIC Tape Technology Roadmap.

LTO Technology Roadmap

The LTO program published the LTO Ultrium Technology Roadmap as a way to show past generation technology achievements as well as future LTO technology targets. The current generation is LTO-8 with a capacity of up to 30TB compressed. The roadmap forecasts future LTO generations aiming to double the cartridge capacity with each generation.  That’s a huge capacity growth that can provide numerous benefits to your organization, including reduced space requirements, increased productivity and lower costs.

How is this capacity achievement possible? Let’s take a look.

Deep Dive

According to the INSIC Tape Technology Roadmap,  Magnetic Tape has a number of technology levers that allow it to significantly increase its storage capability and performance while continuously improving its impressive data integrity and reliability characteristics.  Here are some of the technology levers as reported by INSIC:

Tape Areal Density:  Current LTO and enterprise tape drives operate at areal densities that are about two orders of magnitude smaller than the latest HDDs. Therefore it is possible to continue tape technology at historical rates for at least the next decade. For instance, a 12TB Disk product must use 923 Gb/in2 vs [the] latest 12TB LTO-8 cartridge that only uses 8.5 Gb/in2. Meaning, tape can achieve the same capacity with only 1/108th of the areal density than that of the disk. The combination of tape area and the ability to increase areal densities is the main reason why tape can continue to enjoy  that level of capacity growth as illustrated in the INSIC Areal Density chart (Figure-1) and seen here. Recent laboratory tape areal density demonstrations also provide evidence of the potential to continue scaling tape technology to areal densities of up to 201Gb/in2.

Why Tape is More Reliable than Disk: Tape is a multi-channel storage device with two-dimensional orthogonal, highly interleaved ECC protection called C1 and C2. C1 and C2 are highly efficient Reed-Solomon Error Correcting Codes (ECC). C1 is designed to detect and correct media errors per channel. C2 is also an ECC code however it is configured to operate in Erasure code to correct any residual errors from C1 engines. For example, 1 error event in 1019 user bits versus the best disk can offer which is 1 error event in 1015 user bits, meaning that tape is 10,000 times more reliable than disk based on Bit Error Rate (BER) specification.

There’s more! 

The INSIC Tape Technology Roadmap offers an in-depth analysis of the growth that’s predicted for LTO tape technology’s capacity. The LTO tape technology roadmap is strong and can continue to provide the data protection and economic advantages that many have come to appreciate. Fred Moore, Horison Information Strategies, noted “In the future, I believe tape volumes will dramatically increase because of the price, performance, capacity, reliability and roadmap advantages.” – See a user case study here.