Although HFS is considered as the most efficient and reliable partition, but sometimes it has been found that under certain condition users needs to repair HFS volume. There are various possible factors which can be responsible for HFS volume corruption but the most reasonable cause is damaged or missing file system. In such circumstances users are simply unable to use their system and all the existing files will also gets inaccessible. However if the corruption is minor then you can repair HFS volume easily with the help of disk utility. It is an built in utility, used to repair the damaged or nonfunctional disk on Mac system. But in case of any severe corruption you will need to format the hard drive in order to repair HFS volume on Mac. It is an ultimate option to fix any corruption or performance issue on Mac. However it is advisable to use it as the last option only. As it wipe the entire hard drive thus it will remove all the files and documents stored on Mac drive in order to resolve the issue completely and repair HFS volume. Fortunately with the help of Mac Data Recovery Software all your lost or formatted files can be restored easily.