Tape has been used for data storage since the early days of computing in the 1950s. For decades, it was the primary medium for backup and archiving. While other technologies like hard disk drives and flash storage have become more popular for daily use, tape remains a crucial part of many organizations’ data storage strategies.
Tape has unique advantages that make it well-suited for long-term data retention. However, it also has limitations that impact performance and accessibility. Evaluating the pros and cons of tape helps determine when and how to use it compared to other storage media.
The benefits of tape
Here are some of the main benefits that make tape worthwhile for certain storage needs:
Low cost per gigabyte
The biggest advantage of tape is its low cost per gigabyte compared to hard drives and flash memory. Once data is written, tape cartridges can be removed and stored safely offsite at little additional cost. This makes it very economical for large backup and archival datasets.
Long-term durability
Tape cartridges stored properly can last 30 years or more. The media does not degrade over time like optical discs and magnetic storage. This makes tape ideal for long-term archiving where data will be rarely accessed but must be retained intact.
Energy efficiency
When not being actively written to or read from, tapes use no energy. They do not require electricity to maintain the integrity of data. This offers huge power savings compared to spinning hard drives.
Security
The portable, offline nature of tape provides additional security benefits. Tapes can be physically transported offsite to protect backups from natural disasters, cyber attacks, or other threats. When not in a drive, tapes are disconnected from networks or devices that could be compromised.
High capacity
Modern tape cartridges can store enormous amounts of data, up to 60 TB for the latest LTO-9 format. Single cartridges hold far more than disk drives. This reduces the number of media units needed for large archives.
Built-in redundancy
To improve resilience against errors, built-in redundancy allows most enterprise tape drives to continue reading data despite dust, scratches or minor defects. Some formats use multilayer media and advanced error correction to eliminate the need for manual tape rotation or archiving to new media.
The limitations of tape
While tape retains some clear advantages, it also comes with restrictions you need to consider when deciding if it will work for your use case:
Slow data transfer speeds
Even with compression, tape reads and writes data at just hundreds of megabytes per second – vastly slower than hard drives or flash memory. This makes it impractical as primary storage for applications requiring frequent random access.
Sequential-only access
Tape is inherently sequential-access media. To reach a given part of the data, the drive must physically wind past all preceding sections. This rules out random access needed for things like operating systems and databases.
Time-consuming restoration
The process of locating, mounting and reading back required data from tape can take hours or longer. This may be unacceptable for backup scenarios requiring rapid recovery after data loss or system failure outside of large-scale disaster recovery.
Vulnerability to damage and wear
While durable, tape media is still vulnerable to damage, wear and environmental conditions over time. Proper storage and handling is critical. Tape may require periodic baking or drive cleaning to maintain integrity and extend lifespan.
Proprietary media and hardware
Enterprises are locked into a specific vendor’s tape format once invested in drives and media. Changes between generations can require expensive upgrades. Finding working drives for obsolete formats is difficult. This complicates long-term readability of archived data.
Capacity scaling complexity
Expanding tape capacity requires purchasing additional cartridges and drives. Capacity cannot be added gradually like joining hard drives into a single volume. Managing very large tape archives becomes increasingly complex over time.
Use cases where tape storage makes sense
With both the strengths and limitations of tape in mind, these are ideal use cases where it can be the best storage medium:
Archival and backup
The low cost, high capacity, longevity and portability of tape make it optimal for archival requirements and long-term backup retention. While retrieval may be slow, this data is rarely accessed and benefits from tape’s energy efficiency and offline security.
Disaster recovery
Tape is commonly used to store full system backups as part of broader disaster recovery plans. The ability to take tape cartridges offsite and store them for years allows recovery from catastrophic events like fires, floods or ransomware attacks.
Big data and scientific research
The enormous capacities of tape enable cost-effective storage at scale for massive datasets like those generated by scientific research, medical/genomic sequencing, astronomy and physics experiments. Access latency is less critical for these applications.
Cold storage in the cloud
Some cloud providers offer cloud archives or cold storage tiers that write rarely accessed data to tape rather than more expensive disk-based storage. Customers get low-cost capacity by tolerating higher latency when accessing the data.
Media distribution and storage
The entertainment industry relies heavily on tape for video production workflows as well as final media distribution. Tape remains a convenient physical delivery mechanism while optical discs are declining. Reusable tape cartridges also have environmental benefits compared to discs.
Tape vs. disk vs. flash storage
Here is a high-level comparison between tape and the two other major storage media, hard disk drives (HDD) and solid state drives (SSD):
| Attribute | Tape | HDD | SSD |
|---|---|---|---|
| Cost per GB | Lowest | Middle | Highest |
| Access speed | Slowest | Middle | Fastest |
| Durability | Highest | Middle | Lowest |
| Portability | Highest | Low | Lowest |
| Energy efficiency | Highest | Middle | Lowest |
As this comparison shows, tape tends to represent an extreme – it has the lowest capacity cost and highest longevity but the slowest performance. HDDs and SSDs take the middle ground and opposite extremes on other attributes. This leads tape to be most appropriate for infrequently accessed data where storage density and retention matter more than speed.
The future of tape storage
While no longer central to most computing applications, tape continues to fill an important role that is not going away. Tape capacity, reliability and cost advantages ensure it will remain viable for the foreseeable future. However, there are some key trends that will shape tape storage going forward:
Increasing capacities
Ongoing advances in tape technology will continue driving cartridge capacities higher. LTO-10 aims to reach 120 TB per tape when it launches around 2025. Higher capacities reduce media costs but increase the data loss impact of any single tape failure.
New use cases
As the Internet of Things (IoT) generates more data from smart devices and sensors, tape may gain appeal for cheaper edge storage. 5G networks will enable faster data transfers to speed up tape workflow bottlenecks.
Improved access latency
Future tape formats may close the performance gap with disks by improving read/write speeds. This could expand tape’s usefulness for secondary storage tiers, not just archives.
Integrated cloud archives
Major public cloud providers already offer large object storage tiers based on tape. Cloud archives accessed directly over high-speed networks eliminate physical media handling and make tape storage available on demand.
Declining market share
Tape now makes up just a few percent of the overall storage market in terms of capacity shipped each year. This downward trend will likely continue as higher performance options get cheaper. But tape will still play a key role in massive archives.
Conclusion
Tape has major advantages for long-term data retention thanks to its low cost, energy efficiency and durability. Transfer speed and access latency shortcomings make it unsuitable for primary storage. Tape works best for backup, archival and disaster recovery situations where data is rarely accessed but must be preserved at scale. While no longer the default storage choice, tape should remain a vital part of the technology landscape well into the future.