Error Erasing External Hard Drive Mac
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a problem, while handling some of the Macs, when they are not allowed to repair permissions or directory in Disk Utility. They are unable to erase or partition the drive. Even the Network deployment tools like how to clear an external hard drive Apple's Netinstall service or the DeployStudio fails, on account of this error. The error, which
Volume Erase Failed With The Error
is thrown, is the: ‘Disc erase failed couldn’t unmount disc.' or ‘Disk Erase failed with the error: Couldn’t unmount disk.’ The error disk erase failed with the error couldn't open device occurs in such situations like formatting Mac as well as partitioning and verification and repairing of Mac disk. Causes The reason for this error is the modification of the boot drive, or it is being used by https://discussions.apple.com/thread/5812340?tstart=0 some other process or application. If the internal drive is causing the issue because the OS X Recovery exists as a partition on the physical disk, unable to modify or unmount the internal drive, then the preference must be given to a network drive or an external drive. Solution There are many solutions when the user faces these problems. Using an external drive or OS X Recovery for the starting up of the Mac http://www.stellarinfo.com/blog/couldnt-unmount-disk-error-mac/ from another bootable drive. Disk Utility can be run from the external drive. The version of the OS X does not matter, by at least must be 10.7, 10.8 and 10.9. The one and only requirement are that Disk Utility must reside on the drive. There are three means of resolution of the problem. These are: (1) Fixing with Partition Manager If the OS X is denying you to format, erase and repair the Mac hard drive or a volume due to the Couldn’t Unmount Disk’ Error then use Partition Manager Application to format the hard drive with Mac OS X Extended Journaled file system. Formatting the hard drive or partition scheme will recreate new HFS file structure on the hard drive, which will be free from cryptic errors. Further, the disk manager utility will allow the user to create, resize, add partitions on the hard drive with HFS, FAT or NTFS file systems. (2) Fixing with USB Boot Drive This is the most recommended method to repair the error. Any OS X boot drive is needed to complete the task. But, the important point to remember is that the installer or the recovery drive must reside in the drive, separate from the primary boot disk with the installed OS on it. The following steps can do the fixing: The USB boot
Start here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers http://apple.stackexchange.com/questions/125965/unable-to-format-erase-hard-drive or posting ads with us Ask Different Questions Tags Users Badges Unanswered Ask Question _ Ask http://osxdaily.com/2013/06/14/resolve-a-couldnt-unmount-disk-error-in-disk-utility/ Different is a question and answer site for power users of Apple hardware and software. Join them; it only takes a minute: Sign up Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top Unable to format / erase hard drive up vote 11 down vote favorite 3 I have an external hard external HD that died on me a while ago and I'm trying to see if I can format / erase it to start using it again. The disk does not show up in Finder but I can see it in Disk Utility. When I try to erase it from there I get Disk Erase failed with the error: POSIX reports: The operation couldn’t be completed. Cannot allocate memory When I try to verify the volume: diskutil verifyVolume /dev/disk2 Error starting filesystem external hard drive verification for disk2: Unrecognized filesystem (-9958) I've tried running a surface scan in Techtools Pro, it processed 650 blocks and all were bad. I cancelled the operation cause it was very slow. Diskutil info /dev/disk2 tells me: Device Identifier: disk2 Device Node: /dev/disk2 Part Of Whole: disk2 Device / Media Name: WD Ext HDD 1021 Media Volume Name: Escaped with Unicode: Mounted: No File System: None Partition Type: None Bootable: Not bootable Media Type: Generic Protocol: USB SMART Status: Not Supported Total Size: 2.0 TB (2000396746752 Bytes) (exactly 3907024896 512-Byte-Blocks) Volume Free Space: Not Applicable Read-Only Media: No Read-Only Volume: Not applicable (no filesystem) Ejectable: Yes Whole: Yes Internal: No OS 9 Drivers: No Low Level Format: Not Supported I've also tried: diskutil eraseDisk JHFS+ Stef2TB /dev/disk2 Started erase on disk2 Unmounting disk Creating partition map Waiting for disks to reappear Formatting disk2s2 as Mac OS Extended (Journaled) with name Stef2TB Error: -9944: File system formatter failed Can I salvage this drive somehow or is it ready for the trash? hard-drive disk-utility share|improve this question edited Oct 26 '14 at 14:24 nschum 1285 asked Mar 30 '14 at 8:28 stef 2132511 Did you find the answer in the end? Im having the exact same issue.. –user88264 Aug 20 '14 at 12:37 add a comment| 5 Answers 5 active oldest votes up vote 10 down vote I found this worked perfectly (from the terminal): diskutil eraseVolume ExFAT MyName diskX You'll
halt whatever the attempted task is right in its tracks. This can happen during partitioning, disk verification and repair, and even during formatting, and there's usually little to no additional information provided as to how to resolve the problem or even what the problem is. Typically the "Couldn't Unmount Disk" error pops up when the currently boot drive is being modified, thus the easiest solution is to boot from another drive and run Disk Utility from there instead. For the boot drive, it shouldn't matter which version of OS X it's for (assuming 10.7, 10.8, and 10.9 at least), the only requirement is that it has Disk Utility - which they all do. This will allow you to fix the problem, regardless of the cause, by one of two means, the first is a sure-thing to fix the issue, while the other only works sometimes. We'll cover both with a bit of explanation. Resolve the Unmount Error with a USB Boot Drive This is the recommended method because it should always fix the error. You will need any OS X boot drive to complete this task, I used a Mavericks boot installer drive for this purpose but others should work too, whether they are installation drives or just recovery drives, the important thing is they are bootable and separate from the primary boot disk that stores the installed OS: Attach the USB boot drive to the Mac and reboot Hold down the OPTION key during boot, then select the attached boot drive (typically has an orange icon at the boot menu) At the boot menu, choose "Disk Utility" (if using an Installer disk, pull down the "Utilities" menu to access Disk Utility) Go to "First Aid" and verify the disk, then repair if needed Now perform the original task that threw the "Couldn't Unmount" error I ran into this twice recently, first when attempting to modify partitions on a drive, which came right along with a separate "partition failed" error, and again was triggered when attempting to format those partitions. The above steps did the trick and everything was working again as expected. This is a good example of why it's very valuable to have a bootable USB thumb drive set up with whatever version of OS X is run