External hard drive not mounting/mounted in macOS Mojave/High Sierra, how to recover lost data? M3 Mac Data Recovery can easily recover data from unmounted external hard drive in macOS Mojave 10.14/10.13/10.12 and Mac OS X.
Posted by Admin to on April 26th, 2017 Since updating to macOS Sierra, my Seagate 3TB external hard drive is not mounting by macOS High Sierra 10.13/10.12 Sierra. In Disk Utility I cannot do anything but format it which I don't want to do, because there are many important files stored on it, any suggestions to or? Solution 1: Repair unmounted external hard drive with macOS built-in Disk Utility Although macOS built-in Disk Utilitiy has the ability to repair unmounted external hard drive, but in some situations, Disk utilily cannot repair this disk.
Back up as many of your files as possible, reformat the disk, and restore you backed-up files: In this situation, data recovery from unmounted external hard drive is the best way. After data recovery is done successfully, use the disk utility to reformat the unmounted external hard drive, then the unmounted external hard drive will be working again. Solution 2: Recover data from external hard drive not mounting on Mac is a professional Mac data recovery software which can recover data from external hard drive not mouting on Mac computer, recover deleted files even if emptied from trash, recover data from unreadable, formatted, corrupted drive on macOS Mojave 10.14//Sierra 10.12 and Mac OS X 10.11/10.10/10.9/10.8/10.7 and supports APFS, encrypted APFS, HFS, HFS+, exFAT and FAT32 file systems.
Tutorial to recover data from unmounted external hard drive with M3 Data Recovery Step 1: Download, install and then launch M3 Mac Data Recovery on your Mac computer. Step 2: Select the volume or external hard drive Step 3: M3 Mac Data Recovery is scanning lost data from unmounted external hard drive Step 4: Select the found files you expect to recover and then click Recover to recover lost data from unmounted external hard drive.
After data recovery from unmounted external hard drive is successfully done, please try to reformat it, it will be working again after format completes.
Hardware Issues Provided your hard drive works properly and doesn't suffer from physical defects, you shouldn't expect to see unusual slow downs in performance. External hard drives usually don't support the S.M.A.R.T (an acronym for Self-Monitoring, Analysis and Reporting Technology) status that can warn you of a pending hardware failure. However, you can check to see if your hard drive supports the feature. Click the 'Go' menu, select the 'Utilities' folder and open 'Disk Utility' to check the status. Select the external hard drive and check the S.M.A.R.T Status section.
A normally functioning disk should show as 'Verified.' If the hard drive doesn't support the technology, it shows as 'Not Supported.' Software Issues Permission and file issues can create problems and slowdowns on an external hard drive. You can repair your file permissions and fix some problems with your hard driving using the built-in Disk Utility. Open Disk Utility, choose your external drive and select the 'Repair Disk' and 'Repair Disk Permissions' options, if available. If these options are greyed out, click 'Verify Disk Permissions' and 'Verify Disk.' Reboot your computer and try accessing your hard drive again once the permission repair is complete.
Power Supply Some external hard drives work while not connected to a power supply, but function more efficiently when not reliant upon the computer to draw power. Firewire, USB and Thunderbolt cables can run off your MacBook when it runs on battery power or while plugged in to a wall charger.
If you have several components that draw power connected simultaneously, it could create more drain on your power supply and cause less than optimal performance with your externally connected hard drives. When possible, connect your hard drive to an external power supply for the best performance. Hard Drive Defragmentation If you have enough free space on your computer's internal hard drive, you can also try moving all of the files from the external hard drive to your computer, then formatting the external hard drive and move the files back. This defragments the files on the hard drive. Normally, you don't need to format files on a Mac since the operating system does it automatically. If you consistently work with large files, have little available free space and conduct video or audio editing, though, your computer could benefit from defragmentation. Solid state drives don't suffer from fragmentation, and defragmentation of an SSD drive only reduces its life span.