Hello everyone! I am new to this forum and hoping for some advice with this hard drive issue. I opened a brand new Lacie 500 GB Hard Drive. It is connected to my macbook via usb. I selected it as my hard drive destination in Time Machine and ran the backup option. The hard drive did mount. About 5 minutes in the backup option failed - a time machine error: time machine backup failed. I ejected the drive and unplugged it/turned it off and rebooted my laptop. Now the hard drive does not mount on my desktop however will show in disk utility. It lists with the Lacie name and another subdivision under the name. When I try disk repair, erase or partition..I always get the same message: resource busy. After the error, the hard drive subdivision disappears leaving only one name on the list in disk utility. (It does not have the name underneath it). I apologize for my semi technical description. I am new to mac and appreciate any advice on how to fix this issue. All I want to do is backup my laptop using the new hard drive with time machine. If any one knows how to remount the drive I would be very thankful.