How long do hard drives last?

Hard drives don’t last forever. Eventually the precision parts that let them rotate at thousands of RPM per minute with read heads that float just microns off the disk surface wear out and fail. SSD drives fail too, just in different ways. Modern technology has made them so reliable that we can be lulled into thinking they won’t give us problems, but that is a false security.

The truth is, an HHD or SSD drive can fail at any time. The best data we have, from online backup provider BackBlaze, proves it. Having a new drive is no insurance. It can fail just as easily at 100 hours as it can at 20,000 hours.

Here’s the part where I remind you that luck is not a strategy to keep your data safe, multiple backup copies is, before I return to the main subject.

So really you shouldn’t ever feel safe about a drive, and should have a disaster plan in place to fix things when, not if, they fail. Because given enough time, it is a when.

Drives record how long they have been powered up in internal logging called SMART data. Some drive cases allow us to read this data and see how many hours drives have been turned on. And while drives can die at any time, they become more likely to die as they log more hours.

Knowing a drives age in hours can be useful. I feel pretty comfortable using a HDD for 20,000-25,000 thousand hours based on my experience maintaining the servers for my printing companies, and my use of hundreds of drives.

25,000 hours/24=1041 days or 2.85 years of continuous use.

But chances are you only need access to your data for a few hours each day, so you can make your dives last a lot longer by powering them down or having them spin down when not in use. Some drive cases like drobo and synology let you specify when drives should “sleep.” Others need to the USB or power to be unplugged or switched off.

At 8 hours a day, 5 days a week, 52 weeks a year, you’ll log about 2,000 hours a year on your drives, and it will take you over ten years to get to 25,000 hours, by which time we should have some Star Trek like crystal storage technology, or at the least, much much cheaper cost per TB, and you’ll have probably replaced your current drives with much larger version for convenience. Less hours spinning means less chance they will fail.

But assuming you are really using your drives a lot, once drives approach 30,000 hours, I like to rotate them out of my master level storage and downgrade them to backup, where they will see fewer hours of use per year. While I’ve had drives work for over 50,000 hours, I wouldn’t want a drive that old to be used for anything but backup for a host of reasons.

All this applies to HDD drives, traditional hard drives with spinning disks. SSD, or flash drives have their own issues, not the least of which is loosing data if not powered on regularly. As of yet, there are few ways to safely put your data on a shelf for a long time and just forget about it. Your data needs to be kept alive on fresh drives and properly backed up, and only you can do that.

So how long do hard drives last? Until they don’t! Which will be the worst possible time they could fail based on Murphy’s law.

Hard Drive Costs November 2019

Current hard drive costs at a glance with links to purchase from Amazon. I recommend Seagate hard drives because they continue to test as some of the longest lasting drives.

Highlight for November is that 10TB external drives are a big savings over 10TB Internal drives. Also, on a cost per TB basis, 10TB drives are getting close enough to the sweet spot of pricing to make them attractive. But I generally don’t recommend buying more than a year’s capacity at a time, because 10TB drives could be $100 by next November, and will erase any “savings” from buying more than you need now. Also remember that a properly backed up “storage set” requires three drives, so buying more than you reasonably need (over provisioning) can suck up a lot of money.

Sometimes external drives are less expensive than internal drives. Advanced users may want to explore “shucking” external drives to save money as the external drives are often, but not always, SATA drives that can be used as an internal drive.

EXTERNAL

2TB $59.99 ($30 per TB)
4TB $89.99 ($22.50 per TB)
6TB $99.99 ($16.60 per TB)
8TB $139.99 ($17.50 per TB)
10TB $179.99 ($18 per TB)

INTERNAL

2TB $49.99 ($25 per TB)
4TB $89.99 ($22.50 per TB)
6TB $131.99 ($22 per TB)
8TB $149.99 ($18.75 per TB)
10TB $249.99 ($25 per TB)
12TB $312.99 ($26 per TB)
14TB $439.99 ($31.40 per TB)
16TB $476.99 ($29.80 per TB)

I’m an Amazon affiliate so I receive a small commission from each sale.

Drobo Cost Calculations

UPDATED 2019-10/31 with link to Google Sheet

At what point is buying a Drobo worth it compared to using single external drives? And what size drives should you buy for the best value? To help a friend with this question and satisfy my curiosity, I created this spreadsheet that you can access on Google Sheet.

Using 8TB drives gives the best value per TB. If you need more than ~21TB (dual drive redundancy), it’s cheaper to buy a second Drobo than it is to use 10TB, 12TB, or 14TB drives. And “upgrading” the drives in an existing DROBO usually isn’t worth it, unless all your drives are so old that they just need replacing anyway.

PRO TIP: Drobo is NOT a backup. It merely makes your master data more resilient to drive failures. A backup is a separate copy on a separate device, and you need two backups. Keep one backup off site to protect agains fire, flood, theft, tornados, hurricanes.

If you are going to buy a Drobo, use my Amazon Affiliate links and I’ll get a small commission:

Drobo 5C

8TB Internal Hard Drive