Will Flash Replace Disk?

People often ask me when disk drives will be replaced by some newer technology, like bubble memory or holographic memory or flash memory. Last time I got this question, the person aimed me at this article: Flash for Laptops: Computers that use flash chips instead of a magnetic hard disk for memory are coming.

So will flash replace disk drives? Two answers:

I don't think so. For high-capacity storage systems, I don't think flash or any other new technology will replace disk drives any time soon.

I don't care. From NetApp's perspective, I don't think it really matters, because I don't think it would have much effect on our technology or our business.

Now I'll dig more into each answer.

I don't think so.

It makes great sense to replace disks with flash in small portable devices. Flash has already replaced disks in the iPod, and I've been craving a laptop made with flash for a while - lighter, more shock resistant, less power, no spin-up time. I want one!

But for high-capacity storage, flash is just too expensive. On the web, I can get a 250 GB SATA drive for $160, or $0.64 per GB, while 1 GB of flash costs $20 - thirty times as much. Even more for high-speed flash. Of course, flash is getting cheaper pretty fast, but disks have an amazing track record of getting bigger and cheaper. Technologies like perpendicular recording, Heat Assisted Magnetic Recording (HAMR) and Bit Patterned-Media (BPM) promise to continue this trend well into the future.

Of course, there are other potential competitors to disk, like holographic storage, but they keep not shipping. I'm not saying that nothing will ever replace disks, but I'd be very surprised if any new technology were shipping in sufficient volume to replace disk drives five years from now. And it wouldn't surprise me at all if disk drives were still the high capacity medium of choice even ten or fifteen years out.

I don't care.

Having said all that, I don't really care very much one way or the other, because I doubt that a new storage technology that replaced disk drives would have very much effect on NetApp or our competitors.

My guess is that most of our storage and data management capabilities will still be required no matter what this new technology is. For instance, I bet that it won't be 100% reliable, so we'll still need RAID-like technologies to protect against failure. We'll still need remote replication to protect against disasters. Pretty much any capability you can name - backup, snapshotting, encryption, compliance, thin provisioning, application integration - will still be necessary, so what difference will it make whether we buy disk drives or some futuristic new storage device?

If the new technology doesn't emulate disk interfaces, then maybe a few device drivers will change. If it isn't a spinning media, then some optimizations we do to deal with seek times will no longer apply. Maybe some new optimizations will be needed instead. But other than that, I just don't think it'll be that big a deal to replace disks as the underlying storage technology.