How the Pros Determine Hard Drive Failure Rates

How the Pros Determine Hard Drive Failure Rates

May 5

Having the guts of your computer peter out at any time is not fun. Experts say hard drives are the least reliable. So is there a way to determine just how long your particular hard drive will last?

Well, if you’re lucky enough have a spare $30,000 available, you could buy the hard drive made from sapphire that scientists are predicting will last 1 million years.

Don’t have that kind of cash or longevity? Well, then, you may be interested in one of the various studies that found the average age of different hard drive models.

San Mateo, California-based Backblaze is the company many source when reporting on hard drive failure rates.

The company looks overall across 30,000 hard drives and found that the average failure rate is 4 percent with hard drives living a median life span of about six years, Gleb Budman, president and CEO of Backblaze, said.

Last year, Backblaze gave a detailed account of how they tested hard drives to determine the failure rates.

Budman explained that there is a process. The first is when drives are “shucked,” meaning the internal drive was removed. Then it was inspected for any damage – bent things, missing things, chipped circuit board.

Next, Backblaze performs a SMART snapshot: Self-Monitoring, Analysis and Reporting Technology used to monitor hard drives to detect and report on various indicators of reliability.

After that, Budman said there was a fair amount of burn in and load testing, which includes putting the kind of data on it that would be representative of the kind of data that would be part of Backblaze’s applications. They delete all of the data and take another snapshot, running it for several hours to several days before it goes into production. From there, software monitors the drives.

Other than being gentle with the hard drives, there isn’t much that can be done to prolong the mortality of a hard drive. Budman said one of the things that impacts hard drives is vibration, with some research out there showing the advantage of building racks out of something other than steel to minimize vibration.

People worry about heat, but Google research found that heat didn’t actually affect the drive within certain specs.

After evaluating all of those hard drives, Backblaze found that when it comes to failures, it is a bathtub-shaped curve.

“We saw a number of failures at the beginning, then drives would last past the first year and do well for a few years before we saw it hit a steady rate of failure,” Budman said.

He puts to rest some misconceptions about age, saying it isn’t a steady decline during the six-year average life span, and the drives are not totally reliable for five years and then die in the sixth year.

The best way to ensure a good hard drive life is find a specific model and get a good drive within that model. That’s because within an individual vendor, Backblaze found variations in failure rates, from 4 percent to 14 percent. One even had a 120 percent failure rate — Budman said that means the drive might work for eight months before failing.

Could hard drive manufacturers produce drives that last longer? Perhaps, but Budman thinks they are focused on other things driving purchases like density and performance.

“I’m amazed when people say these drive manufacturers make such junk,” he said. “I’m amazed the drives work as well as they do and for as long as they do. They have multiple platters spinning at 7,200 rpms a few microns away, 24-7 for five years, after which more than half of the drives are still working. That is an incredible feat of engineering.”

Photo Credit: Wikimedia Commons