Data loss causes

Among the most common data loss causes are:

Accidental deletion of a file or folder

Depending on the file system, each OS acts differently to delete a file. For Windows FAT file system the OS marks file directory entries as unused and destroys file allocation information (except beginning of file), for NTFS – just marks file entry as unused, deletes record from directory and marks disk space as unused; for most Linux/Unix file systems it destroys file descriptor (information about file location, file type, file size etc.) and sets disk as free.

The main purpose of each file deletion is to release storage space used by the file for a new file. Storage space is not wiped immediately (for performance reasons) making actual file data remain on a disk until this storage space is reused to store a new file.

File system format

File system format can be started by mistake, for example, by specifying a wrong disk partition or unclear actions as to storage handling (e.g. NAS devices usually format internal storage after attempt to re-configure RAID).

Format procedure creates empty file system structures on the storage and overwrites any information below. If file system types coincide, it destroys existing file system structures by overwriting them with the new ones; if file system types differ – the structures are written to different locations and may destroy user data.

Logical damage of a file system

This kind of failure may occur due to power loss or hardware failures. Sometimes logical damages are also caused by software failures. Modern file systems have a high level of protection against file system logical damages, nevertheless, useless against hardware or software malfunctions.

Even small piece of wrong data written to a wrong location on the storage may destroy file system structures, break file system object links and make file system non-readable.

Loss of information about partition

This kind of failure may occur due to different reasons, including failed 'fdisk' operation or user errors that usually results in loss of information about partition location and size.

Storage failure

If you detect any physical problems on the storage (e.g. storage doesn't start, makes unusual noises, overheats much, has problems to read data etc.), it's not recommended to take any actions by yourself. You should bring the storage to a specialized data recovery laboratory.

If a failure has occurred to a RAID system which redundancy allows to recover data without single storage (one drive failure for RAID5, no more than two drives failure for RAID6 etc.), it's possible to recover data without the missing drive.

HDD Recovery Experts recovers data from failed hard drives commonly caused by:

  • Mechanical failure (hard drive clicking, grinding, or unusual noises)
  • File system damage (lost data, will not boot, drive not accessible)
  • Bumped or dropped on the wallfloor.
  • Viruses or user sabotage
  • User error such as accidentally deleted files or formatting
  • Static electricity, power surges and outages
  • Natural disasters such as lightning strikes, fires and floods

If you have suffered a hard drive failure or computer crash, please contact us.