With the exponential growth of data, companies are looking for cost-effective ways to store all of that information. In the past, tape storage was a popular medium for data archiving but was replaced by faster and more convenient hard disk drives (HDDs) and solid state drives (SSDs). However, in recent years tape technology has improved dramatically and tape is making a comeback as an archive solution. Let’s look at some of the key reasons why tape usage is increasing and the pros and cons of using tape versus other storage mediums.
What are the benefits of tape storage?
Here are some of the main benefits of using tape for data archiving:
- Low cost per terabyte – The cost per terabyte of tape is significantly lower than HDDs and SSDs. Tape scales well economically for storing large amounts of infrequently accessed data.
- High capacity – Modern tape cartridges can store up to 60TB of compressed data, allowing huge amounts of data to be stored in a small physical footprint.
- Long term retention – Tape has a 30 year or more shelf life if stored properly. This makes it ideal for long-term data retention and archiving needs.
- Energy efficiency – Tapes at rest consume almost no energy compared to spinning hard drives. This can provide major power savings especially for larger archives.
- Physical durability – Tape media is rugged and can withstand more extreme temperatures, vibrations, humidity and magnetic fields than other forms of storage media.
- Air-gapping – Storing tapes offline and off-site provides an air gap against cyber attacks such as ransomware.
- Portability – Tape cartridges are small and lightweight making them easy to transport securely to different locations for disaster recovery purposes.
For large organizations with significant archiving needs, tape provides unmatched storage density and energy efficiency at low cost.
What are the downsides of tape storage?
Tape also comes with some downsides, including:
- Slow data access – Retrieving data from tape is a sequential process which is much slower than random access devices like HDDs and SSDs.
- Limited shelf life – Tapes need to be rewritten every 5-10 years to maintain data integrity.
- Vulnerable media – The physical tape media is delicate and can be damaged by debris, humidity and temperatures beyond specs.
- Drive compatibility – Choosing future-proof drives is important as backward compatibility is not always assured.
- Higher management overhead – Tape libraries require physical management like changing cartridges and ensuring cleanliness.
For these reasons, tape is best suited for infrequently accessed data where access speed is not critical. The management overhead also means tape is most cost-effective at larger scales.
How has tape capacity and cost improved?
Early tape drives stored only a few megabytes, but capacities increased rapidly with new formats like DDS, AIT, DAT, LTO, and IBM 3592. Here’s how tape capacities have grown over time:
| Tape Format | Year Introduced | Native Capacity |
|---|---|---|
| DDS-1 | 1989 | 1.3GB |
| DDS-2 | 1993 | 4GB |
| DDS-3 | 1997 | 12GB |
| DDS-4 | 2001 | 20GB |
| DAT-320 | 2005 | 160GB |
| LTO-1 | 2000 | 100GB |
| LTO-2 | 2003 | 200GB |
| LTO-3 | 2005 | 400GB |
| LTO-4 | 2007 | 800GB |
| LTO-5 | 2010 | 1.5TB |
| LTO-6 | 2012 | 2.5TB |
| LTO-7 | 2015 | 6TB |
| LTO-8 | 2017 | 12TB |
| LTO-9 | 2019 | 18TB |
| LTO-10 | 2022 | 36TB |
As you can see, tape capacities have grown enormously thanks to new formats like LTO and compression. The latest LTO-10 drives can hold 36TB raw and can compress data by 2.5x for 90TB+ capacities.
In addition to higher capacities, the dollar per gigabyte cost of tape storage has dropped precipitously. In the mid-1990s, tape cost around $20 per gigabyte. Now with LTO-8, the uncompressed cost is under $0.01 per gigabyte. This massive drop in the cost per terabyte makes tape extremely affordable for massive data archives.
How fast are modern tape drives?
Accessing data on tape is slower than disk, but modern tape drives provide respectable data transfer speeds. Here are the native data transfer speeds of recent LTO generations:
- LTO-5 – 140 MB/sec
- LTO-6 – 160 MB/sec
- LTO-7 – 300 MB/sec
- LTO-8 – 360 MB/sec
- LTO-9 – 400 MB/sec
- LTO-10 – 750 MB/sec
So while not matching the 500+ MB/sec speeds of modern HDDs, modern tapes can still read and write data reasonably quickly. Software compression can also double effective speeds. Connecting drives via faster interfaces like Fibre Channel instead of SAS provides additional speedup.
What are the main vendors and formats?
The main enterprise tape drive manufacturers are IBM and Quantum who offer proprietary formats plus drives compatible with the open LTO standard:
- IBM 3592 – High performance enterprise tape drive with native cartridge capacities up to 10TB.
- Quantum Scalar i3/i6 – Mid-range tape libraries supporting both LTO and proprietary TS11xx tape formats.
- LTO – Open standard mid-range tape format with roadmap up to 48TB capacity per cartridge.
For smaller businesses, HP, Quantum and Sony still offer drives for legacy formats like DDS, DAT and AIT which provide lower capacities but are cheaper for smaller data sets.
How does tape usage compare to disk and cloud storage?
Despite the rise of disk and cloud storage, tape remains a key part of the data storage hierarchy:
- Disk is best for primary storage where fast access is needed.
- Cloud is convenient for backup, archiving and data sharing.
- Tape offers the lowest cost for infrequently accessed data and long-term archival.
According to surveys by the LTO Consortium, tape capacities continue to grow at around 15% annually. Tape is most widely used by large enterprises and governments who archive vast amounts of data. For example, Square Kilometre Array, one of the world’s largest radio astronomy projects, will generate over 1 exabyte of data per day and plans to use tape systems to store this data long term.
What are some examples of modern tape use cases?
Here are some examples of how organizations today leverage tape storage:
- Video archives – Media companies store large video repositories on tape for long term preservation.
- Scientific data – Research sites like CERN use tape to store massive volumes of physics data.
- Medical imaging – Hospitals and medical centers archive MRI, CT and PET scan images on tape.
- Financial records – Banks use tape for retaining financial transactions and statements for years.
- Government archives – Agencies like the US Census bureau rely on tape to preserve government records.
- Cloud backups – Cloud storage providers may use tape as a backup target for cold data.
These use cases all leverage tape for its low long term storage costs and energy efficiency at scale.
What future improvements are planned for tape?
Tape technology continues to evolve. Here are some future improvements in the works:
- Higher capacities – Roadmaps project cartridge capacities increasing from 36TB for LTO-10 up to 192TB for LTO-13 around 2030.
- Increased speeds – Maximum data transfer rates are expected to reach 1.1 GB/sec for future LTO generations.
- New formats – IBM is working on enhanced TS1160 and Jaguar tapes capable of storing over 40TB natively.
- Improved memory – Flash memory and memory buffer sizes will increase to improve performance.
- Metadata tracking – RFID tags and cartridge memory will store additional metadata on tapes.
- Interfaces – Support for faster NVMe and Fibre Channel interfaces will provide better drive performance.
These enhancements will make tape even more useful for long-term data retention at lower costs.
Conclusion
While tape fell out of favor for primary storage long ago, it continues to thrive as a cost-effective medium for long term data archiving and backup. Thanks to major improvements in capacity, speed, interfaces and infrastructure integration, tape usage is actually increasing, especially among organizations storing massive volumes of data. With a projected roadmap up to nearly 200TB per cartridge and ongoing improvements in performance, tape will remain an attractive option vs. other storage tiers for managing explosive data growth into the future.