My external Thunderbolt drive has been used as a Time Machine drive. Time Machine has somehow decided that the drive is too full for further backups but nis not deleting earlier backups to make space. I decided to erase the drive and start again, but I cannot erase the drive using Disk Utility. I've tried all suggestions and nothing works. Any ideas?
iMac, OS X El Capitan (10.11), October 2013, 27", 32 MB RAM
have yo gone into time machine pref's and disabled it first ?
Yes. I've ejected it, removed it from Time Machine, done everything I can think of, but I can't erase it. If it was behaving as specified and deleting the oldest backups to make room for new backups this wouldn't be necessary, but it's not doing that, it's just been telling me for weeks that it's full.
Here is a screenshot of the result of an attempt to erase the drive. Note the message "Name invalid." I get that message no matter what name I enter. In disk utility the first aid option is unavailable so I can't determine whether the drive itself is faulty. Help, please!
I can't erase my external Thunderbolt drive
