Compact Preferences


General Preferences Safety Preferences E-mail Preferences Update Preferences Files to Delete Compact Preferences Metadata Preferences Optimize Preferences

Compact as much as possible

Enabling this option makes iDefrag try harder to compact the disk, at the expense of a potentially substantial amount of extra time. With this option disabled, iDefrag may skip small gaps to avoid having to move a file twice.

Allow overlapping file moves (unsafe)

This option tells iDefrag that it is permitted to move a fragment to a position that would overlap the current position of that fragment. This opens the possibility of data loss should something untoward (such as a power failure) occur whilst moving the fragment and so this option is considered unsafe.

Note that using the ‘Stop” button is always safe.

Respect file system metadata area policy

On file systems with a metadata area (also referred to as the “Hot Band” or “Hot Zone”), enabling this option prevents any compaction from taking place within the metadata zone.

N.B. metadata areas are only present on journaled volumes of over 10GB in size. Smaller or non-journaled volumes do not have a dedicated metadata zone.

Compact B-Tree files

If enabled, when running the Compact algorithm, iDefrag will attempt to squeeze unused space out of the B-Tree files that are used to keep track of the locations, names and sizes of files (as well as a variety of other information).

Note that this option only controls this behaviour for the Compact algorithm.

Rebuild rather than just compacting

Instead of simply compacting the existing nodes in a B-Tree file, this option causes iDefrag to completely rebuild the B-Tree files before running the compaction routine on them.

Maintain existing ordering of files and fragments

Every bit of free-space on the disk is filled by moving all data beyond it. This of course will take much longer than otherwise but has the benefit of keeping all files in the same order on disk.