I have an external hard drive (WD Elements 1TB) that I use for Time Machine backups on my Mid-2015 Retina MacBook Pro 15" with macOS Sierra 10.12.3.
Lately, the drive doesn't get mounted any more when I plug it in. In Disk Utility, I see two instances of the drive when it is plugged in. When I unplug it, one of the instances disappears. The other one stays, even when I select "Eject" from the context menu. After a reboot, the "ghost instance" is gone, and the drive gets mounted again on plugin. But after one or two eject/unplug/plug-in cycles, I have the same problem again. Time Machine doesn't do backups to the drive unless it is fully mounted.
Is there any way to forcibly "eject" the "ghost" of the unattached drive?
As requested, here's the output of "diskutil list" and "gpt show":
$ diskutil list /dev/disk0 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *1.0 TB disk0 1: EFI EFI 209.7 MB disk0s1 2: Apple_CoreStorage Macintosh HD 999.7 GB disk0s2 3: Apple_Boot Recovery HD 650.0 MB disk0s3 /dev/disk1 (internal, virtual): #: TYPE NAME SIZE IDENTIFIER 0: Macintosh HD +999.3 GB disk1 Logical Volume on disk0s2 2E277268-61D5-4149-B45C-39204E7C1CD8 Unlocked Encrypted /dev/disk2 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *1.0 TB disk2 1: EFI EFI 209.7 MB disk2s1 2: Apple_CoreStorage TimeMachine BFD 999.9 GB disk2s2 3: Apple_Boot Boot OS X 134.2 MB disk2s3 /dev/disk3 (external, virtual): #: TYPE NAME SIZE IDENTIFIER 0: TimeMachine BFD +999.5 GB disk3 Logical Volume TimeMachine BFD on disk2s2 A7F8C874-D9AE-4818-98EE-C4D6F5DC610A Locked Encrypted Offline Logical Volume TimeMachine BFD on disk2s2 A7F8C874-D9AE-4818-98EE-C4D6F5DC610A Locked Encrypted $ sudo gpt -r show disk2 gpt show: unable to open device 'disk2': Device not configured $ sudo gpt -r show disk3 gpt show: unable to open device 'disk3': Resource busy
and two screenshots of Disk Utility:
External HDD attached:
External HDD not attached: