disk erase failed could not unmount disk

You may see Fseventsd process and it’s process id in the list, use “sudo kill -9” to kill this process.Īdditional Information: List Open Files (lsof) is a useful tool that will show you opened files. “lsof | grep” then drag the drive to the terminal window to complete the path to the drive’s mount point, and press enter. To terminate the Fseventsd process, login to Terminal and type in: Events are logged in the hidden “.fseventsd” directory at the root of the drive. It is to log the changes in the file system. You may want to login to Terminal mode and check if there is any process locks down the drive for example: fseventsd process.įseventsd is a file system “events” notifier, running as a daemon process, used by Spotlight, Time Machine and other 3rd party softwares. There is a chance that some background process may lock the drive and prevent it from being formatted, please turn off Spot Light and Time Machine.įor more information about Spot Light and Time Machine, please visit:ģ. If your drive has been used under Windows, it might be in Windows NTFS / FAT format, you will need to change the partition format to GUID partition or Apple Partition Map in order to format and mount the drive in disk utility.įor more information about partition in Mac OS disk utility, please check: How do I partition my drive in Mac OS X®?Ģ.

Please do the trouble shooting as following:ġ.

Disk erase failed could not unmount disk