Keeping you Mac's hard drive or SSD healthy is hugely important. By monitoring and checking your Mac hard drive's health, you can anticipate potential problems and prevent potentially catastrophic crashes.
Fortunately, there are a number of tools available that allow to to check the health of a drive and fix problems before they become serious.
One of the best apps for alerting you to potential problems is iStat Menus, available in Setapp. Once you've installed it, iStatMenus sits in your Mac's menu bar and monitors not just your hard drive, but its CPU, RAM and network traffic, among other things.
iStatMenus, and the other disk monitoring tools available for macOS, monitor what is knows as SMART status. SMART stands for Self-Monitoring, Analysis and Reporting Technology and is installed on most hard drives and SSDs. In order to use it, you need software to analyze and display what it finds, and that's where iStatMenus comes in.
Monitoring SMART reports won't prevent your hard drive from failing, but it will reduce the likelihood of problems occurring.
Note: As of 2016, Apple no longer allows software tools to check the SMART status of an SSD. So iStatMenus won't repot anything on Macs shipped in 2016 or later.
There are other steps you can take to keep your hard drive or SSD healthy. CleanMyMac, also available in Setapp, has a number of maintenance routines. While most of them are designed to keep your Mac running smoothly, one of them is an excellent way to keep your hard drive in good shape.
Sectors are blocks of space on a disk drive and bad sectors are blocks that cannot be read because, for whatever reason, they're damaged. When Disk Drill, available in Setapp, attempts to recover data from a hard drive that's failed or one where you've mistakenly deleted files, it marks sectors it can't read from as bad. That means that it won't try to recover data from them in the future.
You can't fix bad sectors, the drive's firmware should identify them and prevent them from being written to. If there's data stored in them and you need to recover it, you're out of luck. But by monitoring how many of them there are on a drive, you can keep an eye on its health and decide whether it's time to replace it, if the number of bad sector starts to increase quickly.
Here's how to identify bad sector in Disk Drill:
You should always backup your hard drive regularly, but it's even more important to do it when you suspect your hard drive is having problems. If you identify problems with a hard drive using any of the steps above, you should consider increasing the frequency of your backups and test them to make sure you can recover data if you need to – a backup routine is useless if you can't restore data. You should also consider using Get BackUp Pro to make a complete clone of the drive, that way, in an emergency you can boot from the clone and be back up and running immediately. Click here to read about how to backup your Mac. Get Backup Pro, also available in Setapp, is an excellent tool for making regular backups.
If it's already too late and your hard drive has failed and lost data, you should try to recover the data before you do anything else. You can read more on how to use Disk Drill to recover from a hard drive failure and get your data back.