Don’t perform a secure erase on a solid-state drive, such as the ones built into modern Mac Books-that will just wear down the drive for no advantage. Note that this feature will only be useful on mechanical drives, as you shouldn’t be able to recover deleted data from a solid state drive. RELATED: How to Securely Wipe a Hard Drive on Your Mac One pass should be good enough, but you can always do a few more if you feel like it. You can use this feature to securely wipe a hard drive. Click a drive, then click the “Erase” button, then click “Security Options” to select a number of passes to overwrite the drive with. You can also choose to only erase its free space. The Erase button allows you to erase an entire hard disk or partition. Simply click the drive you want to check, then click the “First Aid” button. Be warned that these checks can take a while, and running them on your system drive will leave you with an unresponsive computer until it’s done. This feature checks the file system for errors and attempts to correct them, all without much intervention from you. If a hard drive is acting up, Disk Utility’s First Aid function is the first thing you should try. RELATED: How, When, and Why to Repair Disk Permissions on Your Mac One of them: volumes on the same drive pool storage space, meaning you’ll see two separate drives in Finder, but won’t have to manage how much storage space each volume uses. To add a new APFS volume, simply select your system drive, and then click Edit > Add APFS in the menu bar. APFS is Apple’s new file system, the default on solid state drives as of macOS High Sierra, and it’s got all sorts of clever tricks up its sleeve. If you want to repartition your system drive, you’ll need to do this from within Recovery Mode, with one exception: APFS volumes.

RELATED: APFS Explained: What You Need to Know About Apple's New File System Note: Many of these operations are destructive, so be sure you have backups first.

Clone mac with disk utility