How to help keep your hard drive alive: A tale of 3 studies.
Hard drives are everywhere. They are in your phones, in your car, in your computer and also in the cloud. You interact with hard drives countless times per day and never give them a second thought that is until they fail. We've all been there, sweating bullets and biting our nails at the news that one of our hard drives has failed. Did I just lose all of my data? Is that project gone? Typically the solution for this is to back up your data... onto another hard drive. So in a sense we can never really escape the specter that is hard drive failure. In this article I am going to summarize three different hard drive studies that have been done over the years, each looking at a different aspect of hard drives and the how and why they fail.
First off we will look at a study that was done by Google back in 2007. This article went into great depths regarding hard drive failure trends. Their results showed several interesting observations. First off, hard drives that run at extreme temperatures (under 25c or over 45c / under 77f or over 113f) are much more likely to fail than hard drives running at more moderate temperatures (25-45c / 77f-113f). In most circles the thought is that you want all of your temperatures to be low. CPU's, memory and most other computer related equipment will run better when the temperature drops but with hard drives there seems to be a negative effect. Drives that operated at temperatures of between 25-45c (77f-113f) for their first two years of usage had an average failure rate of around 2% while drives that consistently ran at 20c (68f) had an average failure rate of almost 9%. In the end, running a drive at very low or very high temperatures does indeed have an adverse effect on lifespan. Most server room hard drives are within the 25-45c (77f-113f) temperature range but often times other drives may not be operating in these ideal conditions such as an overheating laptop. So my first advice on keeping your hard drive alive is to keep it at an acceptable temperature.
The second interesting observation in this paper was regarding SMART errors. These errors are typically encountered when a hard drive runs a self-diagnostic and it reports back with an issue. These errors usually indicate an imminent drive failure and are usually taken very seriously in the IT community. This study showed that after a drives' first SMART error a drive is 39 times more likely to fail within 60 days than a drive with no SMART error. While this is a great conformation that the SMART tests that hard drives perform are indeed working as a great predictive indication of an upcoming drive failure it is also worth noting that they also found that 36% of all failed drives had no SMART errors at all. My second bit of advice is to listen to take these errors seriously, if you see one I would immediately back up your data and prepare for an upcoming failure.
All in all I think that what we can learn from this first study is that your hard drive will fail at some point but keeping it at the right temperature and listening to the warning signs can help you prevent data loss. The last thing I'll show from this paper is the annual failure rate per year of the drives in this study. So... how old is your hard drive?
The second study we will be looking at is from an online storage company called Backblaze. They have a massive amount of consumer grade hard drives that they use for their storage media. With over 27,000 drives (totaling over 78,000 Terabytes or 78 Petabytes) they have a great interest in what brands are the most reliable. In their storage arrays they have 3 major brands of drives: Seagate, Western Digital and HGST. There are all very popular brands in the consumer space and most people that I know have very defined allegiances with one brand or another. Below we will take a look at a chart showing the average failure rates over the last few years.
As you can see there is a very clear result over 36 months. Both Western Digital and HGST (formerly Hitachi) both have very low failure rates while Seagate has quite a high average rate of the same 3 year span.
A lot of times you do not have a choice of hard drive in a machine that you are buying but knowing more about what brands are more reliable will help you make a better decision. When you're at the store looking to pick up a cheap laptop or basic desktop a quick look under the hood could help you make a better informed decision. All of these drives have a warranty of at least a 1 year and some of them have even have a 3 or 5, but it won't do you much good if the drive fails suddenly while you're in the middle of something.
In this article we looked at three different studies that related to hard drive reliability. We learned that some brands are better than others and also the impact that temperature; both low and high, have on a hard drives lifespan.
The third article that we are going to look at is a study on the potential lifespan of Solid State Drives or SSDs as they are known in the industry. For those who are not as up to speed on new computer technology, I will give a brief description and use case for Solid State Drives.
While mechanical hard drives have a series of spinning magnetic disks inside of them and SSD uses NAND flash memory which is similar to a USB thumb drive. With no moving parts SSD's are very impact and heat resistant making them a perfect replacement for your laptop hard drive. The other thing that an SSD is good at is speed. SSD's are typically 4 to 5 times faster than a mechanical hard drive, making them a great choice for power users.
There are few drawbacks are typically associated with SSD's and the first one is the price per Gigabyte. A typical 1TB hard drive sells for about $70 while a typical 1TB SSD goes for $400. Prices for SSD's are getting lower and lower and I would expect that one day maybe 10 years from now the price for a HDD and an SSD will be about the same.
The second drawback for a SSD is its longevity. SSD's occasionally have an area of their storage go bad and the drive has to use stop using that space and instead use space from a reserve amount of space. Once that reserve space runs out the drive will no longer function properly. Think about that game snake, after playing for a long time there is just no more usable space left to play and the game ends.
When SSDs first hit the scene a few years ago there was not a real sense of how long these drives would last during typical use, some feared that the drives would run out of usable space after only a year or two of heavy use. The third article that we will look at shows just how long some of these SSDs will last. It turns out that some of them are really good at playing the snake game.
Many of the drives in this test failed at about 600TB of data written, to put that into perspective you would have to completely fill, delete and refill your 1TB SSD every day for almost 2 years for the drive to fail. This is not something that anybody I know does and having your SSD fail due to running out of usable space is not something that you should be concerned about. Most manufacturers state that these drives will be able to write 20-40GB of data per day for their entire duration of their warranty. Even this amount is more than any normal user would do.
There were 2 remaining SSDs in this test that went beyond the 600TB mark are still going strong after more than 2 Petabytes of written data, that's 2000 Terabytes of data written onto them. Using the manufacturers' estimates of 40GB per day it would take about 137 years for this drive to fail by running out of usable space. Suffice to say it's probably not an issue.
Now that's not to say that all SSD's will last that long, there are other reasons that a drive will fail much like a mechanical HDD, but their yearly failure rates are usually less than that of a HDD. A typical HDD might have a 20% chance to fail after 5 years while an SSD is closer to 10%. So if an expensive, smaller, faster and more reliable storage drive is what you're interested in then an SSD is for you.
I have summarized the basics from this article below for quick reference. I hope that you are better informed for your next computer or storage drive purchase.
Ryan's Quick Tips:
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Buy a good brand.
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Keep your hard drive at a reasonable temperature.
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Listen to the signs of failure.
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Back up your data regularly.
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Impact and vibration are your enemy.
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For more speed and reliability go with an SSD.
For a look at these entire articles please see the below links:
http://research.google.com/pubs/pub32774.html
https://www.backblaze.com/blog/what-hard-drive-should-i-buy/
https://www.backblaze.com/blog/hard-drive-reliability-update-september-2014/
http://techreport.com/review/27436/the-ssd-endurance-experiment-two-freaking-petabytes
Field Engineer
Ryan Popke
805-692-6700 x118
[email protected]
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