The code base for Defrag is common for Longhorn and Windows Vista

Feb 2, 2007 12:17 GMT  ·  By

According to Microsoft, there's more than meets the eye as far as the defragmentation process in Windows Vista goes. Defrag was revamped in Windows Vista, and the overhauling has been met with criticism due to the fact that Microsoft has scrapped the Defragmenter display reducing user control and interference to a minimum, by automating the process.

Victoria House, one of the Microsoft Defrag developers explained Vista's defrag changes on The Filing Cabinet. "One change that's not obvious to users is our shadow copy optimization during defragmentation. Defrag has special heuristics to move file blocks in a way that will minimize the copy-on-write activity and shadow copy storage area consumption. Without this optimization, the defragmentation process would accelerate the deletion of older shadow copies," said House.

Microsoft revealed that at the basis of its decision to not include a progress indicator in the Defragmenter display is the process not being a non-linear one. "Instead of trying to show estimates of how much longer the defragmentation process will take, we worked to reduce the impact of defragmentation on your computer, so that you can use the computer during defragmentation. This benefit is gained by using low-priority disk and CPU I/O," stated House.

In Windows Vista, the defragmentation process will not touch certain fragmented files. In this regard, coalescing two extents larger than 64 MB will only produce a minimal performance increase. Microsoft has considered that the I/O load and free space requirements are simply not worth the CPU I/O and free space necessary to move the 64-MB fragmented file.

"Right now we are working on Defrag in Windows Server "Longhorn." If you're in the beta for Longhorn, you'll have a chance to see what's new in upcoming builds. We're also working on improvements to decrease the amount of time it takes to defragment a volume and provide better defragmentation. Because the code base for Defrag is common for Longhorn and Windows Vista, the improvements we make in the server version will be added to Windows Vista SP1," House added.