How to mount a drive using Disk Utility on Mac

Mounting a disk simply means to make the disk available for OS X to perform read and write operations on it. Generally, mounting is an automatic process and happens when the hard drive is connected to Mac. Drive mounting can be done manually using Disk Utility found under Utilities folder. If everything is working fine on the disk, it should be visible on the left-hand-side menu of Disk Utility. Select the disk and click on mount to make it accessible by the operating system. At times, it may happen that the disk is not detected automatically. The later part of the article covers the possible issues with issues that may arise and solutions to fix the same.

Mounting Issues on Mac

After connecting the hard drive to the system, it may not show up as the connected devices. In addition, the Disk Utility may display an error message saying could not mount the disk or may freeze while the mounting process. From the number of possible reasons for this to happen, below listed are few common issues:

1. Incorrect formatting of the disk: The disk that needs to be connected to the Mac system has be formatted in Mac OS Extended (Journaled) format or other Mac supported formats. If this is not the case, the disk will not be recognized.

2. Corrupt Disk: The disk or files residing on the disk may be corrupt and are preventing the disk from being accessible on Mac.

3. Unsafe removal of disk: The most common reason that damages the disk is removing the disk from the system without properly un-mounting it from the system. This corrupts the disk permissions, which will later prevent the disk from mounting properly.

4. Power failure: A sudden power disruption may damage the connected disk and cause the disk being unable to mount successfully on the system again.

5. Connecting Hardware: The SATA cable or USB through which the disk is connected to the system may be faulty and will prevent the disk from mounting.

Resolving Disk Mount Issues

The most commonly used resolution to fix the mount issue is to simply restarting the system and connecting the disk again to check. If this does not solve the issue, Disk Utility can become a handy tool to resolve the issue.

1. Follow the basic steps of checking whether the disk is properly connected to the system and powered on if required.

2. If the disk is visible in Disk Utility but it did not mount, select the disk and click on Verify Disk. This will check the disk for any errors on the disk that can be repaired. If any errors are detected, click on the Repair Disk to attempt repair of issues found. If this completes successfully, remove the disk and connect it again.

Note: Do not attempt Verify Disk Permissions for volumes not originating from OS X. It is only meant for volumes on which OS X is installed.

3. If above procedure did not work, “live verification” can be performed to fix the issue. Shutdown the system and keeping the disk connected start the system. While the system boots, press Command+R. A menu will be displayed from where Disk Utility can be selected. Select the disk and follow the procedure mentioned in second point.

4. Sometimes, the Disk Utility may not function as desired. In this case, it can be accessed from the Terminal as follows:

· Go to Applications > Terminal

· Enter: diskutil list (This will list out the available volumes)

· Check the volume indetifier from the table that appears.

· Enter: diskutil repairVolume [diskvolume identifier]

Stellar Volume Optimizer

Stellar provides an easy to use third party solution to build the corrupt directories and resolve mounting issues along with range of other solutions. Below listed are the excellent features provided by Stellar Volume Optimizer for Mac:

1. Mac Disk Repair: The software performs a repair of corrupt directories and makes the data accessible on a drive with mounting issues.

2. Volume Journaling: The software is capable of managing volume journaling to prevent the drive from damage to the disks through which the Mac systems do not boot.

3. External hard drives: This software is well equipped with functionality to repair the external disks connected to the Mac in case they become corrupt.


In an event of a disk not being detected, above-mentioned manual solutions may be helpful. If the user has limited technical knowledge to work with Terminal on Mac system, third party software such as Stellar Volume Optimizer comes handy with a graphical user interface. For external disks, it is important to unmount them every time before removing them from the system to prevent the corruption that gives rise to the situation in which it does not mount again.