Where to Put 40 ZBs of Data?

Tape vs Blu-ray – Which is Best for your Business?

big dataIDC projects that by the year 2020 the digital universe will reach 40 zettabytes. That’s 5, 200 gigabytes (over 5 terabytes) of data for every person on the planet. The amazing thing is that this is 50 times more than previous forecasts! A large and growing portion of the information is considered to be “Big Data.”  Where is all of this big data going to be stored long term? Much of it will be cold storage, while although rarely accessed, must be maintained for the possibility of future mining or historical research purposes. Businesses need to store this data in the most efficient, reliable and economical manner; while maintaining access and secure protection of the content. While a few suggest using Blu-ray disc to store this data, tape can provide the best long-term storage option. In this BlogBytes, we will compare these two technologies.

What is Blu-ray Disc?

blurayBlu-ray discs are built on the technological foundation established by DVDs in the pursuit of a high-quality TV viewing and listening experience.  About.com  states in an article that blue laser technology uses a narrower laser than DVDs, which use red laser technology.  This blue laser technology is able to create more storage capacity for the disc. A typical multi-layer Blu-ray disc can store up to 100 gigabytes of content with single stream data rates of 25 to 36 megabytes per second.  Claims have been made for up to 250 megabytes per second with the assumption that it is an aggregate data rate of many Blu-ray drives.

How does Blu-ray Disc compare to LTO-7 Tape?

Let’s examine Blu-ray discs head-to-head with LTO-7 tape including storage capacity, data rate capabilities, cost and media configurations needed to store 1 petabyte of data.


  1. Media prices based on the average price from a random web sampling, August 2016

Summary of Key Attributes

One glaring difference noted in the chart is the large number of media touches needed to recover data from Blu-ray technology. This is due to the fact that Blue-Ray disc’s storage capacity is 60 times lower than a single LTO-7 cartridge. In addition, the data transfer rate for the Blu-ray drive is substantially lower at 36 MB/second compared to the LTO-7 drive data transfer rate of 300 MB/second uncompressed. In order to reach the same speeds as LTO-7 drives multiple Blu-ray drives and discs would likely be needed to recover massive data files. For this review, it is assumed that initial hardware acquisition costs would be similar. The most important initial and ongoing cost is the media to store the content. includeing images, video, audio or databases.

The costs speak for themselves. It costs nearly five times more to store 1 petabyte of content on Blu-ray discs than LTO-7 tape. That breaks down to $100 per terabyte on Blu-ray, while LTO-7 tape is only $22 per terabyte. Note: If the data is compressible, LTO technology supports drive level hardware compression with up to 15 terabytes of compressed storage capacity per cartridge.

Data Access – Streaming Rates – Reliability

Blu-ray technology offers random access to data on a disc media format with an average time to data at approximately 45-60 seconds. With the Linear Tape File System (LTFS), accessing data on LTO tape is a simple and speedy process with an estimated average of 90 seconds time to data.  LTFS makes accessing data on LTO tape easy. The process is much like using a USB drive or removable disk.  Once the data begins streaming with LTO-7 technology, streaming is incredibly fast at up to 300 megabytes per second (native), and up to 750 MB/second compressed. The fast streaming capabilities of LTO-7 technology, especially paired with LTFS, can win the race when it comes to file recovery. It was reported in an ESG study that LTO-7 tape has proven to be highly reliable; even more so than enterprise disk.  To help secure data for the long term, LTO technology supports hardware data encryption, which helps to keep content safe. See the LTO technology roadmap to learn more.

ltfs liveIt’s clear that LTO technology has a significant performance and cost advantage over Blue-ray disc to help achieve efficient and manageable long term data retention, while also keeping important data secure.

See LTFS with LTO-7 tape technology demonstrated live by the LTO Program at IBC in Amsterdam, September 9-13, 2016.