HFS+ (Hierarchical File System Plus), also known as Mac OS Extended, is a file system developed by Apple Inc. It was the primary file system used in macOS from 1998 until the introduction of APFS (Apple File System) in 2017. Understanding HFS+ is essential for users who need to manage older Mac systems or external drives formatted with this file system. This article will guide you through the basics of working with HFS+ on macOS, including how to create, manage, and troubleshoot HFS+ volumes.

Examples:

1. Creating an HFS+ Volume: To create an HFS+ volume, you can use the Disk Utility application or the diskutil command in Terminal.

   Using Disk Utility:

   • Open Disk Utility from the Applications > Utilities folder.
   • Select the drive where you want to create the new volume.
   • Click on the "Erase" tab.
   • Choose "Mac OS Extended (Journaled)" from the format dropdown menu.
   • Click "Erase" to format the drive.

   Using Terminal:

   diskutil eraseDisk JHFS+ NewVolume /dev/disk2

   This command will format the disk at /dev/disk2 with the HFS+ file system and name it "NewVolume".

2. Checking the File System of a Volume: To check the file system of a volume, you can use the diskutil info command.

   diskutil info /Volumes/NewVolume

   This command will display detailed information about the volume, including its file system type.

3. Repairing an HFS+ Volume: If you encounter issues with an HFS+ volume, you can use the diskutil repairVolume command to attempt a repair.

   diskutil repairVolume /Volumes/NewVolume

   This command will check and repair the HFS+ volume named "NewVolume".

4. Mounting and Unmounting an HFS+ Volume: To manually mount or unmount an HFS+ volume, you can use the diskutil command.

   Mounting:

   diskutil mount /dev/disk2s1

   This command will mount the HFS+ volume located at /dev/disk2s1.

   Unmounting:

   diskutil unmount /dev/disk2s1

   This command will unmount the HFS+ volume located at /dev/disk2s1.