How does USB data recovery work? A little history… removable storage devices offer unparalleled convenience by allowing us to take our data with us and to quickly access it on any system with an appropriate reading device. For many years the floppy disk drive was the industry standard, but with such small capacity there was always another contender knocking at the door. Some of the more popular devices, like the Zip and the Jaz, were introduced by Iomega and became the portable media of choice for MAC users, especially in the 1990s graphics industry. Others came along after, like the CD/DVD which was better accepted by both the PC and the MAC world. Consequently they soon became the new standard. Today we have a new contender in the USB flash stick also called Thumb Drive, Flash Drive, USB Stick, USB Pen, or Memory Stick. With its ease of portability, standardized USB interface, speed and larger capacities the USB flash stick has become extremely popular for transporting data from computer to computer.
Data Recovery from removable storage devices is required due to one of two main problems:
- LOGICAL PROBLEMS – In these situations the removable storage device is undamaged and still operational. The data files cannot be accessed because the indexes used by the file system to locate the data have been damaged or overwritten.
- PHYSICAL ISSUES – The removable floppy, CD, DVD, ZIP, Jaz or USB flash drive is NOT operating properly or has become damaged. Physical issues are quite different between the various storage devices but may include:
Bad Printed Circuit Board Dropped or Knocked over Media Scratched Unreadable Sectors Storm Power Outage Damage Defective Memory chip Broken Connector Electronics Defective Damaged Casing Clicking Grinding Noise Fire, Flood, Water Damage Physical damage Excessive heat Cold to Hot Condensation Spin motor bad Media aging Servo positioning track bad System Area corrupt Won’t spin up Humming Vibration Issues Crushed, bent or warped
How we recover your data:
If the problem has been determined to be a LOGICAL issue, we first use specialized imaging software to create an exact image of every readable byte of data from the removable media. As with all our recoveries, once an image is secured, we never access the original device again, preferring to work on a copy thus preserving the original media. Logical issues are resolved by careful analysis to determine exactly what went wrong. Damaged and overwritten file system structures are rebuilt manually or using special utilities. In most cases, whether the result of read errors, re-formatting or deleting files, we will be able to repair or rebuild the necessary file system structure in order to access your data. When you delete or reformat your storage device, the file system basically re-writes the tables or indexes that define where the files are stored BUT the actual file contents will remain untouched.
PHYSICAL issues with spinning removable media like floppy diskettes, Zip & Jaz cartridges, and CD/DVD media are related to ONE factor: the condition of the media. Because we are dealing with only one component of the storage system, there are no electronics or mechanical issues getting in the way with our reading of the data. If a sector of data cannot be read, it is because of physical damage or electrical/magnetic damage to the disk media. Besides cleaning and polishing the damaged areas, there are only a few other methods of reading physically damaged media. We can adjust the amplitude of the read signal coming from the heads which may allow us to read a few more sectors. And if we have sectors with ECC read errors we can use ECC error normalization techniques where we read the sectors thousands of times and create the most likely data from those bits that appear most often.
PHYSICAL issues with USB Flash Sticks are much more complicated. In these cases we must remove the memory chip(s) physically from the flash device and read them individually OR we must source and replace the devices controller chip or IC (integrated component). We then analyze and reconstruct the data to a useable form in much the same manner as we handle SSD or Solid State Drives. The schemes used inside by each device’s controller to manage the flash memory are very unique and complicated. The controller attempts to equalize the writing of data across all the data cells and at the same time avoid using the cells previously found defective. To put the pieces of the data back together we must determine the ordering of the data cells to ensure we use the most current data. Remember to call Magnext for all your DVD/JAZ/USB data recovery.