HFS is a very popular file system in Mac OS X computers. It's always manufactured by Apple Inc. to apply for their desktops, laptops, and server computers. HFS is the base in all Mac OS X file systems, along the lines of HFS+, HFSX, and HFS Wrapper. However, under some situations, this could get damaged because of a number of reasons, which include os malfunction, unexpected system shutdown, virus infection, hardware crash, and user errors.In such instances, the stored data becomes inaccessible and you face serious data loss problems. To conquer these data loss problems, Mac data recovery becomes demand of hour.Corruption renders the Mac OS X disk drive volume un-mountable and thereby it cannot be accessed using normal methods. The file system corruption will be indicated by various symptoms, including a mistake message that pops up should you try to mount the disk volume. Whole body message could very well be exactly like the following one- "-127 fsDSIntErr Internal file system error"The error occurs everytime you are hoping to mount the disk volume. For you to sort out this condition with your Mac machine, you want to discover the basis of that issue and cure your symptoms using Mac recovery solutions.Cause As mentioned above, the trouble occurs on account of corruption yet another internal complications with Mac OS X file system. File system may face inconsistencies due to a massive amount issues, like improper system shutdown, operating system crash, user errors, and faulty hardware.Solution To be able to recover Mac data in these instances, explore from either of the below methods- Try repairing the affected Mac OS X disk drive volume using Disk Utility. It is really an inbuilt tool which helps you fix minor disk problems. Run FSCK command on Terminal in single user mode. It will be the command-based version of Disk Utility. Format the hard drive and reinstall computer. It is best to employ this option as being a last measure only while it removes your precious data within the harddrive and cause further data loss. Recover lost data using Mac file recovery software. The applications are particularly intended to extract lost data to all data loss situations.Third-party data recovery software enable you to handle data loss problem effortlessly and safely with simple slot and read-only design.