Hard drives are the component of a computer that fail most often. Every hard drive will eventually fail. This is why it’s so important to backup your Mac’s hard drive. It’s also prudent to periodically check the health of your Mac’s internal hard drive. I recommend two applications for this purpose: Onyx (free) and SMARTUtility (free trial, then $25).
For about the past decade, most internal hard drives have been equipped with a system that lets them monitor their own health and tries to predict failures. This technology is called S.M.A.R.T., which stands for Self-Monitoring, Analysis and Reporting Technology. Onyx and SMARTUtility rely on this monitoring system to help you to check on your hard drive’s health. It’s important to note that external hard drives do not include SMART technology.
Using Onyx is easy. Download the appropriate version of Onyx for your Mac. There is a different version for each version of Mac OS X from version 10.2 to the current version, 10.12. After downloading Onyx, open it and enter an administrative user name and password. This is typically your user name and password.
Onyx will then automatically present a window indicating that it will check your Mac’s internal hard drive if you click Continue. See the picture below.
Interestingly, Genii at some Apple Stores will use SMARTUtility to help determine if a Mac’s hard drive is failing. Thus, if a client reports problems with their Mac that make me suspect the internal hard drive might be failing, I’ll encourage them to run the demo version of SMARTUtility. If it reports a problem, then I know that Apple will likely concur and will replace the hard drive. SMARTUtility is equally easy to use. Download SMARTUtility, which requires Mac OS X 10.5 or higher. Open it to automatically check your Mac’s internal hard drive and display its status in the lower right corner. You’ll likely see a green button containing the word Passed. You don’t want to see the red button containing the word Failing. SMARTUtility lists a lot more detail than Onyx, but most of it is not directly useful to you or me. If you choose to buy SMARTUtility, you can configure your Mac to automatically open it upon startup and configure it to automatically check your hard drive at regular intervals, such as weekly or monthly.
Monitoring the health of your Mac’s hard drive is not an excuse to not backup your hard drive, but it can be a useful diagnostic tool.