Tape drives are data storage devices that read and write data on magnetic tape. Magnetic tapes have been used for data storage and backup since the early days of computing in the 1950s (Tape drive). Tape drives were once the main way to backup data before hard drives became affordable and widely available. Nowadays, tape drives are still commonly used for backup and archival storage, especially by large organizations and companies.
Tape drives have some advantages for backups compared to hard drives or cloud storage. They are relatively inexpensive for the amount of data they can store and are very reliable for long-term archival storage. However, they are slower and less convenient for accessing data compared to hard drives. Overall, tape drives remain a good option for large scale, offline data backups and archiving, but may not be the best choice for more frequent backups needed by individuals or small businesses.
Cost Savings
Tape drives provide significant cost savings compared to other data storage mediums like hard disk drives (HDDs) and solid state drives (SSDs) when looking at cost per gigabyte (GB). According to a report by Nexstor, storing 20 terabytes of data on LTO-9 tape for one year would cost around $24, while the same amount of HDD storage for a year would cost $200 and SSD storage around $2,000.1 Tape cartridges also have a long shelf life, with some lasting up to 30 years. This allows tapes to be reused over decades, further driving down the long-term costs.
An analysis by The LTO Program Technology Provider Companies found LTO-6 tape storage to have a cost per GB of just 1.3 cents, making it one of the most cost effective data storage mediums available.2 With tape storage prices continuing to fall with each new generation, tape remains significantly cheaper for long-term data retention compared to HDDs and SSDs.
Reliability
Tape drives are known for their excellent reliability and low risk of data corruption. According to Fujifilm, tape is 100 times more reliable than flash SSD storage and 1,000 times more reliable than hard disk drives (Fujifilm). Tape cartridges can have a shelf life of 30 years or more if stored properly, making them ideal for long-term archiving. The tape media is very stable andresistant to environmental factors like heat, humidity, and magnetic fields. Reddit users in r/sysadmin overwhelmingly agree that LTO tape drives are incredibly reliable for backups, calling them an “industry standard” for data protection (Reddit). So the risk of data corruption or loss is very low compared to other backup media.
Capacity
Tape drives offer immense storage capacity on a single cartridge, with current LTO-9 tapes able to hold up to 45 TB of compressed data on a single cartridge (wikipedia.org). This massive capacity allows businesses to store enormous backups or archives on a small number of tapes. For example, each LTO-9 tape cartridge can hold the equivalent of 90,000 digital photos, 15,000 DVDs or 3 million mp3s (salvageddata.com).
Compared to other backup media like external hard disk drives which top out at 10-20 TB, the capacity of a single tape cartridge is far greater. This scalability makes tape ideal for industries like media, healthcare, and scientific research that require backing up very large datasets. Rather than maintaining racks of HDDs, a small tape library can provide petabytes of capacity. The roadmap for future tape drives like LTO-10 and beyond suggests cartridge capacity will continue to grow in coming years, keeping tape as one of the most densely packed storage mediums available.
Speed
Tape drives have relatively slow write and read speeds compared to hard disk drives (HDDs) and solid state drives (SSDs). According to Oracle, tape drive performance is limited by the speed at which data can be written or read at the head/media interface [1]. For example, LTO-6 drives have a minimum speed of 160 MB/s, while a typical 5400 RPM HDD has speeds over 100 MB/s [2].
However, tape drives are designed for sequential access, which matches the use case for backups. Tapes stream data sequentially, rather than seeking randomly like HDDs. This sequential access is optimal for large backup and archival datasets [1]. So while tape drives have slower access speeds, their sequential design makes them well-suited for backup applications.
Security
One of the key advantages of tape drives for backups is the high level of physical security they provide. Since tape drives are offline and removable, the backup tapes can be easily taken offline and stored securely offsite. This makes them much less vulnerable to cyberattacks like ransomware compared to always-online backups stored on hard drives or in the cloud (Source).
Tape drives also support encryption to secure the data at rest, providing an additional layer of protection (Source). The encryption occurs in the tape drive hardware, not the backup software, meaning even if the tapes are stolen, the data remains inaccessible without the encryption keys. Tape encryption provides affordable and reliable data security without impacting backup performance.
The offline, removable, and encryptable nature of tapes allows companies to implement the industry best practice of storing backup tapes offline and offsite. This protects against a wide range of threats including ransomware, insider attacks, natural disasters, and more. Tape drives enable reliable backups alongside robust physical and digital security (Source).
Accessibility
One of the limitations of tape drives is that they do not allow easy random access to individual files like hard disks do. To access a specific file on a tape, you need to scan through the entire tape sequentially until you reach the desired file. This makes locating and restoring individual files from a backup tape time-consuming and inconvenient (TechTarget).
Restoring entire backup tapes also takes considerable time due to the linear nature of tape drives. They have much slower access times compared to hard drives and solid state media. For example, the average access time for an LTO-8 tape drive is about 60 seconds, while a hard drive is less than 10 milliseconds (Wikipedia). As a result, recovering large backup sets using tape can be a lengthy process.
Longevity
An important consideration for tape backups is the lifespan and longevity of tape technology. Tape manufacturers typically advertise a lifespan of 30 years or more for LTO tapes stored under ideal conditions [1]. However, real-world conditions often result in shorter usable lifespans of 10-20 years [2].
A key challenge with tape is that formats become obsolete over time, requiring data migration to new formats. For example, formats like DLT and AIT are no longer supported. As noted by [3], LTO tape is extremely sensitive to storage conditions, and its lifespan depends on factors like temperature, humidity, and magnetic field exposure.
Backward compatibility between LTO formats also poses challenges. While LTO-9 drives can read LTO-8 tapes, there is no guarantee future drives will be backward compatible. This requires migrating data periodically to avoid format obsolescence.
Use Cases
Tape drives are commonly used for both daily incremental backups and long-term archival storage. They provide a versatile solution for a range of users, from individuals to large enterprises.
For daily backups, tape offers a reliable and secure offline option compared to disks that are always connected. Tapes can be rotated out each day for off-site storage, providing an air gap that protects against malware or ransomware attacks. This makes tape well-suited for incremental backups from a disk staging area.
For archival purposes, tape has excellent longevity for storing data that does not need frequent access but must be retained for compliance or record-keeping. Tape cartridges have a shelf life of 30 years or more if properly stored. This makes tape ideal for archiving old projects, medical records, financial documents, and other data sets.
While tape may seem outdated, it continues to fill an important niche for both personal and enterprise backups. Individuals can use tape to create periodic backups of their computer hard drives and protect irreplaceable files. Enterprises often employ robotic tape libraries with dozens of drives and thousands of cartridges to handle their massive storage requirements. Tape scales effectively for backups of large file servers, databases, and virtual machine images.
Conclusion
In summary, the key pros of tape drives for backup are their longevity, security, and low cost per TB. The main cons are their slow speed for backups and restores compared to disk, and the requirement to physically swap tapes for offsite storage. Tape drives are a good fit for archival data that does not need frequent access, as well as for organizations that need to securely store large amounts of data over many years.
Tape drives work best as part of a tiered backup strategy, where disk handles daily incremental backups for faster restores and tape is used for weekly full backups for long-term retention. For home users, tape can provide an inexpensive way to create an offline backup copy of irreplaceable data. Overall, tape remains a relevant backup medium due to its advantages around reliability, capacity, and cost savings.