Smart error Mac hard drive can obstruct you to perform different operations on the drive like copying, moving the file. In some cases you won't be able to install any new program on your Mac system The Self Monitoring Analysis and Reporting Technology is present in the Mac hard drive that checks the health of the drive and notifies any inconsistency in the drive to the user. But sometimes there can be false alarm and messages by the tool about the drive which is responsible for blocking the drive. However the smart error mac hard drive is because of the corruption but not in the drive actually in the utility. You can use the disk utility to make fix smart error mac hard drive but in the end you will have to format the drive which can fix this but the data will be lost. You can recover it with time machine backup but when it fails you can use the mac data recovery software to scan the drive and get back all the files in the drive. You can download and use the software after you fix smart error mac hard drive.