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Algorithms |
Unlike many other defragmentation or disk optimization products, iDefrag supports more than one defragmentation algorithm. Currently, the product has support for five defragmentation techniques, as follows:
Compact
Moves all files on the selected volume to the beginning of the volume. Useful for resizing a volume, or to improve free space fragmentation without running a full optimization.
Metadata
Focuses on the volume metadata and the adaptive hot file clustering system. Volume metadata is moved into the metadata zone (if present), or to the start of the volume and defragmented. Metadata zone policies are enforced; hot files are moved in to the metadata zone, whilst other files are evicted. Files that are no longer on the disk are removed from the hot files B-Tree.
Quick (on-line) (Full version only)
Attempts to defragment fragmented files without unmounting the selected volume. This is only possible for ordinary files; volume metadata, the files with hard links and some other files cannot be defragmented in this fashion.
Optimize (Full version only)
Runs iDefrag’s disk optimization algorithm, which rearranges files on the disk under the control of the selected class set. Files can be grouped or sorted arbitrarily, based upon file name, size, and many other attributes. Note that this does not compact or rebuild the B-Tree files like the Metadata algorithm does.
Full Defrag (Full version only)
Runs the Metadata algorithm and then the Optimize algorithm. If you have set the options to compact or rebuild the B-Tree files in the Metadata preferences, this will be done after running the Optimize algorithm.
All of the algorithms supported by iDefrag are affected by the currently selected class set. For most, the effect is limited to determining whether a particular file can or cannot be moved, although the class set mechanism provides more detailed control over the Optimize algorithm.