Optical Archive Inc., a startup created by a former Facebook infrastructure guru that is using Blu-ray disks in place of hard drives or tape to store files, has been purchased by Sony for an undisclosed sum. The deal, which involves a startup that didn’t raise outside funding and doesn’t have a stated price tag, is significant because it involves Frank Frankovsky, the former head of Facebook’s Open Compute server efforts, who left the social networking company in 2014. It also targets a hot area in the data center world and signals Sony’s entry into selling products for corporate data centers.

OAI, as it is known, was created in 2014 to sell custom-built hardware to large customers who want to access stored documents relatively easily, but not so fast that they want to pay a premium, and put the data they want to access on a high-performance SSD drive. A popular example is Facebook’s stated goal of storing users’ old pictures. The social site collects petabytes of photographs and can’t afford to keep them on costly solid state drives, but doesn’t want to move them to archival methods of storage since a nostalgic user might click on a photo at some point and want it to load relatively quickly.

Frank Frankovsky, CEO of OAI. Frank Frankovsky

That, in a nutshell, is what cold storage is about—finding cheaper ways to store gobs of data in a way that’s accessible, scalable and cost-effective. For most companies, storage comes in three tiers. The fastest, and most expensive are SSDs, the solid state drives that run inside our personal laptops and allow it to boot up instantly. Facebook and others use SSDs to keep data they need quickly.

The next level of performance is hard drives, the traditional spinning disks that one might hear whirring away inside an old computer tower or server. There disks are cheaper, but can store a lot of information. Unfortunately, they are also slower and prone to mechanical failures. Finally, there is still a market for magnetic tape, the microfiche of the storage world, that is cheap but can require days to access to the files you want.

What OAI proposes, is using optical storage—in the form of Blu-ray discs. Using the same media that currently holds my daughter’s Disney movie collection to keep Facebook photos or bank data might seem odd, but Blu-ray has its benefits. Frankovsky says that the disks last up to 100 years in highly air-conditioned data centers, and 30 to 50 years in the more modern, outside air-cooled data centers. Because they are optical, they are less affected by heat and humidity, although dust is a problem.

And you can store a huge amount on each disc. Current discs store about 50 GB per disc because they are made for entertainment, but Frankovsky says the plan is to store 300 GB per disc when OAI launches its commercial product at the end of the year and 1 terabyte of data in the coming years. Instead of the traditional racks filled with boxes that contain hard drives or SSDs, an optical storage system would require a rack, or even a room filled with densely packed discs that a robotic arm can pull up and place on a platter when the data is needed. Imagine an old-fashioned jukebox.

Frankovsky was a bit vague on mechanics and details, because those won’t be revealed until the actual product debuts later this year. Sony may have purchased the startup, but it has done so without OAI having any public customers or a final product in the market. Frankovsky, said a few companies are testing the systems so far. Facebook, which is a very likely test customer, if only because it tests just about every new infrastructure technology out there, already discussed how it’s using Blu-rays for cold storage back before Frankovsky left.

As for the acquisition by Sony, Frankovsky portrays it as a chance to get really big, really quickly, telling Fortune that when it came time to build the product he realized that OAI would need a lot of resources to do it well, and it made more sense to just go in-house at Sony.

“We were getting tons of customer interest, and you know in Jaws the scene where they see the shark coming and they say, ‘We’re going to need a bigger boat?'” Frakovsky says. “Well it was like that for us.” So he sold his three-person startup to Sony so it could get bigger, faster. For its part, Sony can now take Frankovsky’s startup and use it to access the relatively fresh and growing data center market.