A Mac boot volume is the brain of the OS X whose sole job is to load the operating system upon start-up. Sorry to mention this, but if the boot volume fails then user have no choice other than to remain deprived of accessing the Mac computer until and unless the drive gets repaired or replaced with a new one. In general, any physical or logical reasons are directly responsible for the failed hard drives. The failure of HDD is prominent not only in old computers but to my astonishment, many new Mac machines also goes through hard drive failures. New hard drives under warranty or Apple Care are replaceable and may not fetch any additional cost. However data retrieval from the failed drive is another matter of shedding some bucks. In all, the hard drive failure is a costly affair and many a times, an unavoidable disaster.
How to recognize an erratic behaviors of Mac boot volume?
Sound Effects: Modern and new hard drives work quietly and any irregular sound effect from the drive is enough to alert a Mac owner. Anyhow, if a user notices some kind of ‘clicking’ noise from the drive then please feel fortunate enough because the drive has begin prompting you its trouble. Initiating Disk Utility tests as well as SMART test are recommended to get a more clearer picture of the trouble likely to happen to the drive.
No Boot: Many cases of the same, a failed drive will certainly not let the OS boot because of the severe damage done to its surface or the file structure. This now turns into a case of a dead hard drive. It may occur all of a sudden without any prior intimidation. Vice-Versa, much before the death of the drive, the system displays its abrupt behavior in the form of excessive freeze ups, failed hardware tests and failed SMART tests etc.
A Mac OS X will definitely come back to its normal functioning once the drive is either repaired or replaced, although it leaves a question behind on how to retrieve the data back from it. Here are some general methods done to regain the data from the drive:
Clone/Image a Mac Drive: Most users will turn up to clone the failing Mac hard drives in the very first encounter just after they come to know its condition. But, again will cloning help in every cases? Certainly not, a cloned copy is the replica of the original drive that means, the cloned copy will contain the same errors as in the original drive. Still, clone will assist to vanquish slow reads or hardware failures that lies on the original drive. However, Imaging the failed drive over clone will do a more great job because the image of the drive does not copies any bad sectors.
Data Recovery from a failed hard drive through software is only possible when the drive is not physically damaged and still being recognized by Mac, though incorrectly. In an event of physical detriment, the hard drive needs to be brought up in a Class 100 clean room facility (like an operation theater for storage devices) for a thorough examination. This examination is necessarily performed by the data recovery experts to determine the approximate percentage of data that can be successfully recovered before committing to the hard drive owner.