Tape storage devices have been around for decades and are still used today for certain data storage applications, especially for backup and archival purposes. However, tape storage has some disadvantages compared to newer data storage technologies like hard disk drives (HDDs), solid-state drives (SSDs), and cloud storage. The main disadvantages of tape storage are:
- Slow data transfer speeds for reading/writing data
- Risk of data corruption and loss
- Limited lifespan
- Higher long-term storage costs compared to HDDs and cloud storage
In the opening paragraphs, it is clear that while tape has historically played an important role in data storage, it has some limitations compared to alternatives when it comes to performance, reliability and costs. The rest of the article will dive deeper into the specific disadvantages of using tape storage.
Slow Data Transfer Speeds
One of the biggest disadvantages of tape storage is the relatively slow data transfer speeds. The sequential access nature of tape means that data cannot be randomly accessed like with HDDs and SSDs. To locate and retrieve data on a tape, the entire length of the tape may need to be scanned.
Typical tape drive transfer speeds are in the range of 100-200 MB/s for reading and writing data. This is much slower than HDDs which can have data transfer speeds up to 1,000 MB/s or higher. And SSDs are even faster with speeds in the multi-GB/s range.
The slow speeds of tape storage make it unfeasible for applications where fast data access is required. For example, it would not be practical to use tape as the primary storage for a live database system. The delays caused by the slow tape speeds would significantly impact performance.
However, for data archival, the slower speeds are more tolerable. When data is infrequently accessed in cold storage, the tape speed limitations are less problematic. But for any data that needs fast, random access, tape storage is ill-suited compared to HDDs, SSDs or flash memory.
Risk of Data Corruption and Loss
Another downside of tape storage is the potential for data corruption and loss. Tape drives and tapes themselves are mechanical systems that wear down over time. Tape media degrades after repeated reading/writing passes. And the moving parts in tape drives can also eventually fail.
This leads to a few data reliability risks:
- Tapes can deteriorate and become unreadable as they age, leading to total data loss
- Data corruption can occur if parts of a tape are damaged
- Tape drive failures can render data on tapes inaccessible
- Human errors can lead to overwrite or deletion of the wrong tapes
These types of problems are less likely with HDDs, SSDs and cloud storage. Those technologies use electronic components with no moving parts that are less prone to mechanical failure.
To mitigate the data corruption and loss risks, tape storage needs to be paired with comprehensive backup strategies. Important data on tapes must be duplicated across multiple tapes. And a process to periodically refresh tapes by copying to new tapes is required.
Following meticulous backup procedures can minimize the disadvantages. But there is still more risk inherent in relying solely on tape storage compared to other modern storage systems. One study found that the rate of data loss incidents was higher for tape compared to disk and cloud alternatives.
Limited Lifespan
A tape has a limited lifespan and will need to be replaced every 5-10 years on average. This lifespan limitation has cost implications for long term archival storage.
Assuming a mid-range 7 year lifespan, an archival storage system using tapes would need to budget for a complete replacement of all tapes once every 7 years. Replacing an entire tape library is an expensive endeavor.
In contrast, HDDs can retain data for decades if stored properly. Online cloud storage systems completely abstract away hardware lifespan issues from the user. As long as you pay your monthly bill, your cloud data should remain accessible indefinitely.
Maximizing the working life of a tape requires specialized storage conditions like temperature and humidity control. Storing tapes for long periods under suboptimal conditions increases the risk of data loss. So properly managing a large tape archive requires ongoing resources and overhead.
Whereas HDDs and SSDs can tolerate more variability in storage conditions. And clouds remove the need to manage physical media lifespan entirely. So those alternatives avoid some of the long-term costs and overhead associated with tape archives.
Higher Long-Term Storage Costs
While the hardware costs of a tape library and tapes may seem inexpensive up front, the total costs add up when taking the media lifespan and overhead into account.
Several analyses have found that over a 10 year period, an archival storage system based on public cloud storage can represent a cost savings compared to locally managed tape archives.
This cost advantage for the cloud is driven by a few factors:
- No hardware procurement needed for cloud storage
- No maintenance and floor space required for tape libraries
- No staffing overhead for tape handling and rotations
- No costs for periodically replacing tapes
Cloud storage providers can take advantage of economies of scale to keep storage costs low. And they handle all hardware maintenance and replacements behind the scenes as part of the monthly service costs.
For very large archival datasets in the petabyte scale, tape does have advantages over cloud storage costs. But for smaller archives, the public cloud is likely the more cost effective solution over a multi-year period.
And cloud storage eliminates the risks of data loss and corruption by keeping multiple redundant copies distributed across data centers. So while cloud storage costs a little more up front, the long term TCO can be lower while also providing more data durability guarantees.
Limited Functionality
Tape storage devices also have limited functionality compared to disk-based storage and cloud storage solutions. As discussed earlier, tapes only allow sequential access, which significantly limits performance for many workloads.
And the functionality to index, search, analyze and process data stored on tapes is very limited. Tape storage works best as pure cold data storage. Getting value out of data stored on tapes requires first copying it to disk-based systems.
Whereas native cloud storage like S3 offers robust functionality for data search, analysis and processing with attached compute resources. Services like Amazon S3 Glacier Deep Archive provide an archival equivalent to tape while still retaining cloud functionality.
So if you want to actually do anything with archived data other than cold storage, cloud services provide much more robust on-demand functionality. Tape storage is only designed to be cheap offline storage.
Increased Vulnerability to Physical Threats
Tapes are also vulnerable to physical damage, theft, and disasters given their physical nature. They must be handled with care, stored properly, and transported securely to limit risks. If stored tapes suffer flooding, fires, or are mishandled, the data can be permanently lost or corrupted.
Cloud storage and disk-based storage have reduced physical vulnerability. Even if one data center suffers damage, cloud providers replicate data across geographically dispersed locations. So cloud storage avoids single points of failure present with tape libraries.
And HDDs/SSDs can be fairly rugged in withstand shocks, vibration, heat and moisture variation. Tapes require much more tightly controlled storage environments to maximize their lifespan.
Overall, the physical fragility and need for manual security of tapes creates disadvantages compared to automated redundancies in cloud infrastructure and disk storage systems.
Lack of Encryption Standards
Native encryption capabilities for tapes also generally lag behind disk and cloud solutions. LTO-5 standard tapes added AES-256 encryption, but adoption is limited. Many organizations still use older tape formats lacking encryption.
Whereas encryption for both data in transit and at rest is table stakes for any reputable cloud storage provider. And modern disk storage systems also support robust encryption capabilities, like self-encrypting drives.
Unencrypted tapes represent a significant security and compliance risk factor. If tapes are lost or stolen, the data is compromised. Strong encryption is essential for protecting archived data, and tapes often lack native support. So additional encryption steps are required before writing to older generation tapes.
Overall, the encryption capabilities gap between tape and modern storage systems is a disadvantage for securely storing sensitive data long-term on tape. Extra measures are required to provide adequate safeguards.
Lack of Compression Options
Data compression is another area where tape lacks capabilities relative to alternatives. Tape drives support some basic compression, but it is not comparable to modern variable block compression methods.
Cloud storage and disk systems take advantage of compressing data before writing it to increase effective capacity. Many datasets compress by 2x or more with optimized algorithms.
But to store highly compressed data on tape requires first compressing and then decompressing during writes and reads. This adds latency and storage inefficiencies. Storing pre-compressed data nullifies one of the main benefits of tape – its sequential speed.
Lacking compression options increases the effective costs of a tape archive. More raw storage capacity is needed to house datasets compared to leveraging compression. So compression limitations also contribute to the higher TCO of tape solutions.
Vendor Lock-In Concerns
Organizations using tape storage can also get locked into one proprietary vendor’s technology. Tape formats and drives tend to be vendor specific. So switching to a different vendor may require completely replacing your tape library.
Migrating to a new vendor’s tape technology would require costly data migrations. This issue of vendor lock-in reduces flexibility to adapt to evolving price and technology changes.
In contrast, cloud storage relieves provider lock-in issues by making it easier to move data between platforms. And standardized disk storage formats like SAS and SATA allow interchangeable use of drives between vendors. Tape storage can present more challenges when changing course.
Limited Scalability
Expanding tape storage capacity is also not as seamless as with disk and cloud storage. Scaling up tape requires purchasing physical drives, libraries and media. Capacity and throughput scale in large discrete chunks based on installable hardware components.
Cloud platforms and disk offer nearly unlimited on-demand scalability. You can request a capacity increase or faster provisioned performance through an API call or control panel. The infrastructure scaling happens behind the scenes without installing physical hardware.
So tape storage scalability is limited to fixed incremental growth based on available physical resources. Other storage systems offer fine-grained scalability that more closely aligns capacity and performance to changing needs.
Conclusion
In summary, here are the key disadvantages of tape storage compared to HDDs, SSDs and cloud storage:
- Much slower data transfer speeds
- Higher risk of data corruption and loss
- Shorter media lifespan requiring periodic replacements
- Higher TCO for long-term archival storage
- Limited native functionality beyond simple data storage
- Increased vulnerability to physical threats like damage and theft
- Lack of encryption standards leaving data less secure
- Fewer compression options to maximize capacity
- Vendor lock-in reduces flexibility
- More difficult and discrete scaling
Tape remains advantageous for some use cases like specialized long-term archives in the 100s of TBs or PBs scale. But for more general data archiving needs, especially in smaller capacities, HDDs, SSDs and public cloud storage tend to provide better overall value.
The disadvantages around speed, reliability, costs, encryption, compression, scalability and vendor lock-in all contribute to limitations around tape storage in the modern era. Maintaining local tape archives requires ongoing overhead and risks compared to cloud alternatives. And even local disk storage often surpasses tape in many regards beyond just costs.
So while tape retains a niche in some large archives, broader technology advancements are gradually reducing its relevance for more generalized storage use cases. As speed and functionality become more critical across workloads, tapes fail to keep pace with HDD, SSD and cloud innovation.
