It is human nature to assume that if it looks like a duck, quacks like a duck and sounds like a duck then it must be a duck. The same could be said about hard drives. They only come in 2.5” and 3.5” form factors, but when we dig deeper, there are distinct difference and developments in the storage industry that will define and shape the future of storage.

The Rotating Disk or Spinning Disk

So there were many claims in the 90’s of how the “mainframe is dead”, but the reality is, the mainframe is alive and well. In fact, there are many corporations still running on mainframes and have no plans to move off of it. This is because there are many other factors that may not be apparent on the surface, but it is reason enough to continue with the technology because it provides a “means to an end”.

Another claim was in the mid 2000’s that “tape is dead”, but again, the reality is, tape is very much alive and kicking. Although there have been many advances in disk and tape alternatives, tape IS the final line of defense in data recovery. Although it is slow, cumbersome and expensive, it is also a “means to an end” for most companies that can’t afford to lose ANY data.

When it comes to rotating or spinning disk, many are rooting for the disappearance of them. Some will even say that is going the way of floppy disk, but just when you think there isn’t any more that can be developed for the spinning disk, there are some amazing new developments. The latest is…

The 6TB Helium Filled hard drive from HGST (a Western Digital Company).

Yes, this is no joke. It is a, hermetically sealed, water proof, hard drive packed with more platters (7 platters) to run faster and more efficiently that the conventional spinning hard drive. Once again, injecting new life into the spinning disk industry.

What is fueling this kind of innovation into a supposedly “dying” technology? For one, solid state drives or SSDs are STILL relatively expensive. The cost has not dropped (as much as I would have hoped) like most traditional electronic components thus keeping the spinning disk breed alive. The million dollar question is, “How long will it be around?” It is hard to say because when we look deeper into the drives, there are differences. They are also fulfilling that “means to an end” purpose for most. Here are some differences…

1. Capacity
As long as there are ways to keep increasing capacity and keep the delta between SSDs and spinning disk far enough, it will dilute the appetite for SSDs. This will trump the affordability factor because it is about value or “cost per gigabyte”. We are now up to 6TBs in a 3.5” form factor while SSDs are around 500GBs. This is the single most hindering factor for SSD adoption.

2. Applications
Most applications do not have a need for high performance storage. Most storage for home users are for digital pictures, home movies and static PDF files and documents. Most of these files are perfectly fine for the large 7.2k multi-terabyte drives. In the business world or enterprise, it is actually quite similar. Most companies’ data is somewhat static. In fact, on average, about 70% of all data is hardly ever touched again once it is written. I have personally seen some customers with 90% of their data being static after being written to for the first time. Storage vendors have been offering storage tiering (Dell Equallogic, Compellent, HP 3Par) that automates the movement of storage based on their usage characteristics without any user intervention. With this type of virtualized storage management maximizes the ROI (Return on Investment) and the TCO (Total Cost of Ownership) for spinning disk in the enterprise. This has extended the existence of spinning disk as it maximizes the performance characteristics of both spinning disk and SSDs.

3. Mean Time Before Failure (MTBF)
All drives have a MTBF rating. I don’t know how vendors come up with these numbers, but they do. It is a rating of how long the device is expected to be in service before they fail. I wrote in a past blog called “The Perfect Storm” where SATA drives would fail in bunches because of the MTBF. Many of these drives are put into service in massive amounts at the same time doing virtually the same thing all of the time. MTBF is theoretical number but depending on how they are used, “mileage will vary”. MTBF for these drives are so highly rated that most of them that run for a few years will continue to run for many more. In general, if a drive is defective, it will fail fairly soon into the operational stage. That is why there is a “burn-in” time for drives. I personally run them for a week before I put them into production. Those drives that last for years eventually make it back on the resale market only to run reliably for many more. On the other hand, MTBF for an SSD is different. Although they are rated for a specific time like the spinning disk, the characteristics of an SSD is different. There is a process called “cell amplification” where the cells in an SSD will actually degrade. They will eventually be rendered unusable but there is software that will compensate for that. So as compared to a spinning disk where there is no cell amplification, SSDs are measurably predictable to when they will fail. This is a good and bad thing. Good in the aspect of predicting failure but bad in the sense of reusability. If you can measure the life of a drive, this will directly affect the value of the drive.

In the near future, it is safe to say that the spinning disk is going to be around for a while. Even if the cost of SSDs come down, there are other factors that meet the needs for the users of storage. The same way that other factors that have kept the mainframe and tape technologies around the spinning disk is has earned its place.

Long live the spinning hard drive!