To ensure the safe movement of files on Windows NT/2000/XP systems, Diskeeper
uses mechanisms built into Windows NT/2000/XP that were developed and
implemented by Executive Software, and fully incorporated into Windows
NT/2000/2003/XP by Microsoft. On Windows 95, Windows 98, and Windows Me systems,
Diskeeper uses similar mechanisms used by Microsoft and others.
By using these built-in mechanisms, Diskeeper maintains cache coherency, file security and permissions information, and file content integrity no matter how fragmented the files on the disk are.
The foremost design goal for Diskeeper for Windows was to make sure that no data is ever lost. To accomplish this goal Diskeeper uses the following criteria for accessing files:
* the contents of data files are never modified under any circumstances
* The only change to file attribute-type information is the physical location of the file on the volume (no file dates are ever changed, nor are other fields in the file record header used to store Diskeeper information)
* only one file is processed at a time, not the whole disk volume
* each processing pass is independent of other passes
* no information is ever stored on any other device or in a "scratch space"
* Diskeeper accesses a file in such a way that no user access can conflict with Diskeeper during the critical portion of the relocation process
* file relocation is aborted if any error is encountered, leaving the file in its original state
* Diskeeper was designed to err on the side of caution, only moving a file when it is absolutely certain that no data will be lost
* if anything causes your computer to crash while Diskeeper is in the middle of the file relocation process, no data is ever at risk
* Diskeeper never defragments or moves files that are stored at a specific physical location on the volume
As a unique added safety measure, Diskeeper always checks the “dirty bit” of the file system. The dirty bit is a file system indicator that the file system has some inconsistencies. If this dirty bit indicates the file system is damaged, Diskeeper will not run for safety reasons, and will always alert you to this fact. This added benefit of Diskeeper will allow you to maintain healthy disks.
