Like every component in your computer, hard drives can occasionally fail. What sets them apart from every other component, however, are the consequences when that happens. A hard drive itself is replaceable, but the data it holds isn’t. And without an adequate system for backing up your data on a regular basis, you’re putting a lot at risk.

Why Should I Perform Mac Disk Diagnostics?

Diagnosing your hard drive is rarely a top priority for most computer users. Which is unfortunate, because a regular test of a Mac hard drive can have various beneficial effects that can help you get more out of your Mac for a longer time.

  • 😱 It helps prevent unpleasant surprises. By keeping your hard drive in check on a regular basis, you’ll have an early warning when something is wrong and the drive might be headed for failure. This will help you secure your data by running an emergency backup outside of your regular schedule, and will also give you more time to shop around for a replacement drive. This can help you prevent data loss.
  • 📉 It’s a good indicator of the quality of your drive for future reference. Wondering if you got your money’s worth? By regularly inspecting the status of your hard drive, you can figure out if it degrades faster than other models in its price class, or compared to the manufacturer’s specifications. The next time you’re buying a drive for your Mac, you’ll have a good frame of reference for at least one model on the market.
  • 💻 It can alert you to other problems with your computer. Although this doesn’t happen often, sometimes a hard drive inspection can lead to the discovery of other hardware issues, especially in terms of internal device communication. If your computer has been running strangely and your drive analysis shows no errors, this can help you narrow down your search and focus your attention on other areas.

Best Methods to Check Your Mac’s Hard Drive

If you want to check a Mac’s disk for errors and overall health, it isn’t as complicated as it sounds. There are various Mac hard drive diagnostic tools available on the market that can assist you with that, ranging from very easy to use to complex solutions aimed at professionals. Familiarizing yourself with at least one of those suites – and keeping it installed on your Mac – is always a good idea as a responsible computer owner who wants to prevent future problems.

Basic: Check Hard Drive Health of a Mac with Disk Utility

You can scan a Mac disk with your Mac’s own built-in tool for that – Disk Utility. It’s a bit limited in functionality compared to some tools on the open market, but it still gets the job done, and is completely free.

To check your Mac’s disk with Disk Utility, follow these steps:

  1. Start Disk Utility from Applications -> Utilities.
  2. Find your disk in the list on the left side (if you have multiple disks), and click on it.
  3. Click on Info in the top right.
  4. Look at the presented information.

Disk Utility will check the hard drive on your Mac for errors. All results will be listed in the text field in the middle of the window – pay special attention to any red messages. Those indicate errors. Not every error will be critical, and some can be safely ignored, but you should still read over the list in detail.

check your mac hard drive with disk utility

What I liked: Disk Utility is intuitive and easy to use, and available on every Mac by default. This makes it a good option in a pinch.
What I didn’t like: Doesn’t offer as many features for scanning and repairing your disk compared to professional apps on the market, especially if you encounter more serious problems.

Beginner: Test Your Mac’s Hard Disk with Disk Drill

Disk Drill is a data recovery utility that comes with a variety of extra features, including the ability to monitor your drives and check the hard drive health on a Mac. The application can also provide you with information about the current S.M.A.R.T status of your drive.
  1. Install and run Disk Drill for Mac.
  2. Go to S.M.A.R.T Monitoring.
  3. Select your drive, and Click Turn On if it’s not already enabled.
  4. You’ll see the drive’s S.M.A.R.T information presented on the right side.

Disk Drill can also help you recover files you’ve lost to accidental deletion. Try running a scan with it to see what comes up – just go to Storage devices on the left. Normally, no files should end up deleted due to disk failure, but it is possible in an extremely small number of cases. If parts of the disk which contain information about which sectors are occupied by files and which are free get corrupted, this could lead to files being incorrectly marked as deleted.

disk drill for mac

What I liked: Comprehensive analysis and direct support for S.M.A.R.T for Macs that still have it. Advanced data recovery that maximizes your chances of getting back accidentally deleted files.
What I didn’t like: Can seem a bit overwhelming for new users until they get accustomed to the interface – but well worth the effort to adjust.

Advanced: Check Mac Hard Drive Using Advanced Diagnostic Tools

If you’re looking for something slightly more advanced, these tools can help you check your drive in more detail, and provide you with more control over the process. Keep in mind that some of these require advanced skills, so don’t attempt them unless you know what you’re doing.

Option A: GSmartControl

GSmartControl is built on a popular package, smartctl, which is part of smartmontools. It provides a graphical interface to the console application, allowing you to more easily take advantage of its features without having to type long commands in your terminal and stare at the results. It’s one of the easier ways to check a Mac hard drive for bad sectors.
  1. Install GSmartControl and launch it.
  2. You will be presented with a list of your drives. Right-click the one you want to verify, and click View details.
  3. On the next screen, you’ll see several tabs that will show you various details about your drive. The most interesting ones right now are Attributes and Error log.
  4. Under Attributes, you will see a full list of all technical attributes of your drive. Pay attention to Reallocated Sector Count, Offline Uncorrectable, and any row that has pre-failure in its Type column. Any rows highlighted in red/pink should also be checked. You can hover your mouse over different rows to see an explanation of their contents.
  5. If you want to perform more extensive tests, go back to the main screen, right-click your drive, and select Perform Tests. Keep in mind that those can take several hours.
What I liked: Lots of technical information presented with practically no filters – everything you might need to know is there.
What I didn’t like: Can be very chaotic and confusing for inexperienced users, and even for some experienced ones who don’t know what information they’re looking for specifically.

Option B: smartmontools

Unlike most other options on this list, smartmontools works from the command line. This means you’ll have to get your hands dirty in the terminal to use it, which may not be ideal for every user. But if you prefer the terminal for whatever reason, or you’re currently limited to it due to an emergency situation, this can be a great option.

Assuming your drive is in /dev/disk0, here is how to use smartmontools to check its health:

  1. Type sudo smartctl -a -d auto /dev/disk0.
  2. This will provide you with the device’s current S.M.A.R.T parameters.
  3. Type sudo smartctl -d auto -t short /dev/disk0. This will start a “short” test of your drive, meaning that it will run some basic checks but won’t dig into too much detail.
  4. Several other test modes are available – short, long, conveyance, and select. Long tests, as their name implies, take longer to complete, but check your drive in more detail. Conveyance tests specifically check for errors related to physical damage, typically associated with transportation. And with select, you can choose a specific range of addresses to be checked.

smartmontools and terminal on mac

What I liked: Provides a lot of control over the testing of your drive’s health, and plenty of technical details.
What I didn’t like: Not suitable for inexperienced users at all.

Option C: DriveDx

DriveDx does one job, but it does it better than many tools on the market. The application is designed to help you monitor the health of your drives, and features a simple but powerful interface that provides you with immediate access to a wide range of statistics about your drive(s).

To check your drive health with DriveDx, follow these steps:

  1. Install DriveDx and launch it.
  2. On the left side, you’ll see a list of your current drives. Click the one you’re interested in.
  3. The right side of the window will be populated with information about your drive.
  4. Scroll through the list, paying attention to the Status column. Look for any indicators that are below 100%, or marked in a color other than green.

driverdx for mac

What I liked: Fast and simple to use, perfect for users of any skill level.
What I didn’t like: Quite limited in functionality compared to other products.

FAQ

Conclusion

Inspecting the health of your Mac’s drives is not something you need to do every single day, but it’s still a good idea to have some schedule for this and follow it as diligently as possible. It doesn’t take a lot of effort to check Mac’s disk for errors, and once you’ve done it a couple of times, it will be just another routine procedure in the maintenance of your computer and its data, just like your regular backups (which you’re hopefully doing already!)