Switch | Description |
/A | Perform analysis on the specified volumes. |
/C | Perform the operation on all volumes. |
/E | Perform the operation on all volumes except those specified. |
/H | Run the operation at normal priority (default is low). |
/M | Run the operation on each volume in parallel in the background. |
/T | Track an operation already in progress on the specified volume. |
/U | Print the progress of the operation on the screen. |
/V | Print verbose output containing the fragmentation statistics. |
/X | Perform free space consolidation on the specified volumes. |
/R | Performs partial defragmentation (default). Attempts to consolidate only fragments smaller than 64 megabytes (MB). |
/W | Performs full defragmentation. Attempts to consolidate all file fragments, regardless of their size. |
/F | Forces defragmentation of the volume when free space is low. |
Defrag Files Large Than 64 MB
/W | Performs full defragmentation. Attempts to consolidate all file fragments, regardless of their size. in 2008 this switch has been deprecated Undocumented switch : B Use B instead of /W |
Defragment all your drives at once
Would you like to just defragment all of your drives without getting extra info or doing a more complicated defrag? If so, just enter defrag /C and let defrag take over. Or, hey, you could just do this from the main defrag window since it works the exact same.
Other Nice Options
Get more info about the defrag: | /V |
Consolidate free space on a drive: | /X |
Defrag at normal process priority: | /H |
Track a defrag already in progress: | /T |
Defrag all drives except the one listed: | /E |
Defrag all drives at the same time: | /M – note, this is only advisable if you have multiple drives, and will not work good on a computer with multiple partitions |
You can put the options you need together, too. Say you want to defrag all of your devices in verbose mode to see more info, and you also want the defrag to run at top priority. To do this, we’ll enter:
defrag /C /H /V