Check the status of your hard drive on Mac OS X
- Click on the Finder in the dock.
- Cick on Applications in the left panel.
- Click on Utilities.
- Click on Disk utility.
- Click on the hard drive you want to check in the left panel.
- Look at the S.M.A.R.T. status shown at the bottom. Verified means that everything is well while Failure or any other message in red means that your hard drive is defect. Not supported means that the utility does not support that particular hard drive. You can try to check it with Ubuntu it this case. If your hard drive is defect, you should immediately recover data.