Disk vs. tape data backup showdown: which one's game for the long term?

When it comes to protecting data for years to come, one format emerges victorious: tape. This executive guide can help you decide which leading backup method is the best long-term contender for your enterprise.

So it's a battle you're looking for, eh? Disk vs. tape is a face-off to watch. Ultimately, only one format will claim the "Long-Term Data Protection" title.

Like two boxers squaring off, each has strengths and weaknesses. Still, a clear winner has emerged for long-term data backup and archiving: tape. Check out these scorecards to learn why.

Contender #1: Backup tape

In this corner of the ring is tape. Don't let its 60-plus years of age fool you. Like Bernard Hopkins, who at 46 became the oldest boxer ever to win a world title, tape still packs a punch today for thousands of enterprises.

Consider backup tape's advantages:

• Tape provides high-capacity storage. LTO (linear tape-open) is the leading tape backup format. With LTO-8, unveiled in 2017, enterprises can store up to 30TB of data compressed on a single tape. The LTO Program road map shows that the future LTO Generation 12 will store up to 480TB compressed on one tape. This storage capacity should prove useful for the impending zettabyte apocalypse.
• Tape costs are very low. Tape is one of the least expensive options for long-term data archiving. Add in offsite tape vaulting and it still wins against same-size disk arrays. Cloud providers often use tape as a low-cost storage tier as well.
• Call it "Old Reliable." You use a tape only when transferring data to it. After that, it sits on a shelf. It remains offline, unplugged from potential cyberattacks. In contrast, disk data backup systems are constantly whirring, buzzing and humming. Which sounds more prone to breakdown? That's right: disk.
• Tapes have a longer lifespan. When kept clean and stored at proper temperatures, a tape cartridge can last up to 30 years, according to a report by Bloomberg Businessweek. Disk just can't keep up.

Know tape's challenges:

• You'll spend more time seeking your data. Backup tape's seek time improved greatly with the LTFS (linear tape file system) feature. LTFS lets you find data more easily, similar to disks. However, LTFS can't make tape searches faster than disk.
• Maintenance is key. Tape requires attention. To avoid errors, this media must be stored in a pristine environment where its cartridges can be protected from dust and dirt. Tape also still needs to be labeled, logged and tested. This can be tedious and time-consuming.
• It's a longer road to recovery. Storing tapes with an offsite tape vaulting service does lengthen recovery time. That's why you should opt for backing up and storing frequently used, business-critical information in-house or in the cloud.

Did you know that one robotic tape library can hold as much as 278 petabytes of data?

- IEEE Spectrum

Contender #2: Disk systems

In this corner are disks, which require less maintenance and scale easily.

Consider disk backup's advantages:

• You'll enjoy rapid recovery. Finding a particular file on disk is faster than finding one on tape. If your disk is in-house, you also don't have to mess with shipping it offsite. (FYI: Cloud backup is also disk-based, just on someone else's disks.)
• You'll gain efficiencies from deduplication. Deduplication lets you remove duplicate data to free up space. This means you can store data more quickly with less frequent, full backups.

Know disk's challenges:

• You'll pay for convenience. Disk systems are constantly on — and constantly on the verge of running hot. That means you have to give them power and cooling — both costs to consider.
• Always-on data comes with perils. Newer LTO tapes use WORM (write once, read many) security to prevent accidental overwriting. They also are physically removed from a network once written. In contrast, disk systems can be compromised by computer viruses. They can also be accidentally overwritten or reformatted.
• Get your head out of the cloud. If you're thinking cloud storage may be the answer, remember this: Cloud is another form of disk, often with higher costs for data retrieval. Cloud has great uses but still lacks the economy and longevity for large-scale, long-term archiving. Steep ingress/egress charges are also a factor.

The judges weigh in

After the final round, we have a winner. True, an in-house disk system — or even cloud storage — can store many types of data, including recently created and frequently used data. But for long-term storage and access, it pays to keep using tape, preferably stored with an offsite tape vaulting service.