Why does Disk Defragmenter utility not fully defragment a drive?
A volume must have at least 15 percent free space before Disk Defragmenter can completely defragment the volume. If you have less free space available, the operation will run, but only partial defragmentation will result. From a Command Prompt window, runDefrag with the –a switch to see statistics (including free space) the specified volume.
From a Command Prompt window, run Defrag with the –a switch to see statistics (including free space) the specified volume.
You cannot defragment a volume that Windows has marked as possibly containing errors. To troubleshoot this possibility, enter chkdsk d: /f at any command prompt, substituting the letter of the drive in question. Chkdsk will report and repair any file-system errors it finds (after restarting, in the case of a system or boot volume).
Disk Defragmenter does not defragment fi les in the Recycle Bin Empty the Recycle Bin before defragmenting.
Additionally, Disk Defragmenter does not defragment the following files: Bootsect.dos, Safeboot.fs, Safeboot.csv, Safeboot.rsv, Hiberfil.sys, and Memory.dmp. In addition, the Windows page file is never defragmented.
By default, Disk Defragmenter ignores fragments that are more than 64 MB in size, both in its analytical reports and in operation. According to Microsoft's benchmarks, fragments of this size (which already consist of at least 16000 contiguous clusters) have a negligible impact on performance. Thanks to disk latency, a large file divided into 10 fragments each 64 MB or greater in size will not load measurably slower than the same file in a single unfragmented location; under those circumstances, it's best to leave the fragments alone.
Disk Defragmenter will pass over any files that are currently in use For best results, shut down all running programs before running the utility. For even better results, log off and log back on (using an account in the Administrators group) before continuing.
Tags: chkdsk,defragment,memory
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