Symptoms of Unmountable Drive:

Based upon many users’ experiences, the following can be summed up as the symptoms when a drive begins to unmount.Recovery of Data from an Unmounted OS X Mac Drive

  1. A Drive failing to mount either through a firewire or USB.
  2. Files can be seen but any task on them like copies, moving can’t be performed.
  3. The drive may once or twice get mounted luckily but never mounts after that.
  4. Data read/write and access become pathetically slow.
  5. Mac OS X freezes up after the drive gets mounted.
  6. Drive produces strange or any unusual sound indicating either a corruption or physical damage.

Cause of Unmountable volumes in Mac:

We have just read some basic symptoms about unmountable hard drives; now let’s go through the causes of an unmountable hard drive. Here are some:

  1. File system Corruption can make a Mac volume unmountable. The system files once damaged due to over read/write, unsafe unplug from the system, bad formatting of the drive may also be counted as one of the reason for unmountable logical volumes in Mac. Also, at first glance, a user may get confused whether the data present in the volumes is corrupted or the logical volumes itself went through any corruption. To proof check this, try connecting the drive to another system or if Disk utility shows up the drive then run verify permissions. If ‘verify permission’ report will list any errors found on the Mac hard drive. If the report is all well, then you may conclude if only the data is corrupted.
  2. Bad Sectors too can be a strong reason for an unmounted Mac hard drive. They mostly occur if the drive has been through some physical damage. The bad sectors later becomes useless to store data and even if the data stored on bad sector is not easily accessible. The hard drive being sensitive to power fluctuations results in creation of bad sectors on the drive. In the case of bad sectors, the OS X fails to access the data either fully or partially.
  3. Malware causes the hard drive system files to behave in an aberrant manner that could further result in the drive to unmount on a Mac.
  4. Abrupt shutdown or ejection of the hard drive is the most common problem done and faced by users. Because very few of them actually care to eject the media safely, the other drive ejected abruptly causes the drive to go unrecognized by the OS X.

A solution to access the data from an unmounted drive: Considering the points of symptoms and causes of an unmountable hard drive, it’s time now to focus on “How to find out whether the data is intact and accessible from the unmounted drive”.

Recovery from unmounted drives:

  1. Download free file recovery Mac OS X tool from the Internet.
  2. Make sure the drive is attached to be recovered in case of an external drive. Launch the software interface and find the unmounted drive highlighted less prominently than other mounted drives.
  3. Select the unmounted one and begin scan. Be patient and let the drive get scanned completely.
  4. During the scan, the recovery software itself generates the preview of recoverable files giving an idea of the progress to the user.
  5. All complete, the tool now lists every recoverable file to the user and the user can select them for recovery.

Author Bio: Vishal is a technical writer who covers topic on Mac OS X. He keeps experimenting on his MacBook Pro and share useful information with Mac users. You can catch him on Facebook & Google + for more updates on OS X.