How Data is Retrieved After Deleting from Hard Disk or SD Card

Understanding how data is stored on a hard disk (HDD) or a Secure Digital card (SD card) is crucial for anyone concerned with data security and recovery. When data is stored on these devices, it is placed on magnetic strips which use pointers that indicate the binary '1s' and '0s'. When a file is deleted, the pointers remain in place unless overwritten by new data. This article will delve into the inner workings and data recovery methods for deleted files on HDDs and SD cards.

Data Storage Mechanism and Deletion Process

Hard disks and SD cards store data in tiny magnetic strips. These strips use a series of pointers that align in two directions to represent the binary data. When you save a file, the pointers are adjusted to reflect this new data. Upon deletion, only the pointers are removed or marked for reuse, leaving the actual data intact until new data overwrites the space.

To illustrate, consider the analogy of a bookshelf where each book (data) has a label (pointer) showing its location. Removal of a book (file deletion) only means the label is detached and thrown away; the content (data) remains on the shelf (storage device) until new books (new data) come to occupy the space, rendering the old content unrecoverable.

Data Recovery Algorithms and Software

Several algorithms have been developed to aid in the recovery of such deleted data. Popular data recovery software like TestDisk, Stellar Phoenix Mac Data Recovery, and others employ these algorithms to scan and recover data. However, due to privacy concerns, it is challenging to provide a detailed explanation of the exact procedures. These algorithms work by reading the drive for all pointers and checking if the corresponding data is still available. If the data has not been overwritten by new content, it can be recovered.

Video Tutorial and Reminder for Recovery

Remember, once a space has been overwritten with new data, the original content becomes unrecoverable. Therefore, it is crucial to avoid writing new data to the storage device until the last file has been successfully recovered. Utilize data recovery software and seek professional help if needed. Many of these tools and professionals have the necessary expertise and tools to scan and recover the data.