File Storage and Undelete
A Backup Article Contributed by Ashley Lister
File Storage and Undelete
Before anyone can understand the undelete process they need to understand how files are stored on the hard drive. Only then can a user expect to understand how to use any undelete facility. There are a wide range of operating systems and each one his its own method of storing files. Yet, despite these variations, they are all similar in the way they save, delete, and undelete. The undelete process is easier to explain by illustrating the Windows file systems.
Windows and Undelete.
On the range of Windows operating systems, there are three file systems: the 16-bit File Allocation Table (FAT-16); the 32-bit File Allocation Table(FAT-32); and the NT File System (NTFS). In each of these systems the hard drive is divided into clusters of a fixed size. An index in the File Allocation Table of all the file systems identifies each cluster. On those occasions when a file is deleted, its entry in the index is marked to show the cluster (or clusters) are suitable for reuse. A different annotation is used when a file has been undeleted.
The Recycle Bin and Undelete.
On all Windows systems, and with only a few exceptions, deleted files go directly to the recycle bin when they have been deleted. It is also from here that the majority of files can be undeleted. The exceptions to this rule are those occasions when the file is too large for the recycle bin, of if the recycle bin facility has been disabled during the deletion process. Disabling the recycling bin can be accomplished by pressing the shift key during the deletion process.
The recycle bin will not delete files that have been deleted from a network folder and, in these cases, a more comprehensive undelete utility will be required.
Sending files to the recycle bin does not technically delete the information from the hard drive. This first process of deletion merely changes the location of the file's place in the File Allocation Table's directory. The data within the cluster remains the same and, from this environment, files can be easily undeleted.
Consequently, it is prudent to check the contents of the recycle bin if undelete of any kind is required. Usually the recycle bin is accessed from the desktop screen and, once open, it shows a list of files that have been deleted from the hard drive. Performing an undelete from this screen is comparatively easy. After selecting the file required for restoration, either a right mouse click brings up the restore option or it can be selected from the file menu at the top of the screen.
Undelete Programs.
Because of its limitations it is sensible to consider using other undelete programs. The recycle bin is a useful undelete utility but it is not capable of catching every file and a second level of protection is a prudent measure for those who value the security of their files. Admittedly the recycle bin can be expanded in size, allowing a greater amount of files to be saved and stored pending deletion, but this can significantly slow down computer speeds.
