Use fsutil fsinfo ntfsinfo C: to check NTFS volume details like serial number and cluster size. 2. Get file details by ID with fsutil file queryfilenamebyid or queryfileid, requiring admin rights. 3. Create hard links via fsutil hardlink create C:\link.txt C:\original.txt to share file data. 4. Check disk space with fsutil volume diskfree C: for total, free, and available space. 5. Disable 8.3 filenames using fsutil behavior set disable8dot3 C: 1 for performance. 6. Manage sparse files with fsutil sparse setflag and setrange to save disk space. 7. Query reparse points via fsutil reparsepoint query C:\junction to inspect symlinks or junctions. Always run fsutil as Administrator, verify paths, and use cautiously for diagnostics or scripting to avoid data issues, making it a powerful tool for administrators troubleshooting file system behavior.

The fsutil command in Windows is a powerful built-in tool that lets you manage and troubleshoot file systems, particularly NTFS. It allows you to perform low-level operations like checking file details, managing disk space, manipulating hard links, and more—all from the Command Prompt. Here’s how to use it effectively for common file system tasks.

1. Check File System Type and Volume Information

Before making changes, it's helpful to know what kind of file system you're working with.

fsutil fsinfo ntfsinfo C:

This command displays detailed information about the NTFS volume on drive C:, including:

• Volume serial number
• Number of sectors
• Bytes per cluster
• Total free and used space

You can also list all drives on the system:

fsutil fsinfo drives

And get general file system info (FAT32, NTFS, etc.) for a specific drive:

fsutil fsinfo drivetype C:

2. Manage File and Directory Operations

Get File Details (Including MFT Record)

To view low-level details about a specific file, such as its file reference number and creation time:

fsutil file queryfilenamebyid C:\path\to\file.txt

?? Note: You may need to enable debug privileges first using fsutil behavior set disable8dot3 0 or run as Administrator.

You can also query a file by its ID in the Master File Table (MFT):

fsutil file queryfileid C: 12345

Replace 12345 with the actual file ID.

Create Hard Links

Hard links let multiple directory entries point to the same file data on disk. Use fsutil to create one:

fsutil hardlink create C:\link\newlink.txt C:\original\file.txt

Now both paths refer to the same data. Deleting one doesn’t affect the other until the last link is removed.

3. Disk Space Management

Use fsutil to check how space is allocated on a drive.

View Free Space on a Drive

fsutil volume diskfree C:

This returns:

• Total disk space
• Free space
• Available space (accounting for quotas or reserved areas)

This is useful for scripting or diagnosing apparent "missing" space.

Disable or Enable 8.3 Filename Creation (Short Names)

By default, Windows creates short (8.3 format) names for files like LONGFI~1.TXT. You can disable this for performance on SSDs or servers:

fsutil behavior set disable8dot3 C: 1

To re-enable:

fsutil behavior set disable8dot3 C: 0

Check current status:

fsutil behavior query disable8dot3

4. Troubleshoot Sparse Files and Reparse Points

Work with Sparse Files

Sparse files are files that appear large but consume little actual disk space because empty regions aren’t stored.

To set a file as sparse:

fsutil sparse setflag C:\sparsefile.txt

Then set a range of the file as "empty":

fsutil sparse setrange C:\sparsefile.txt 0 1048576

This creates a 1MB sparse region starting at byte 0.

Query Reparse Points (Used by Symlinks, Junctions, etc.)

To see if a file or directory has a reparse point (used in symbolic links or mount points):

fsutil reparsepoint query C:\myjunction

This returns the reparse tag and data, which helps identify what type of link or redirect is in place.

Tips for Using fsutil Safely

• Always run Command Prompt as Administrator—many fsutil commands require elevated privileges.
• Be cautious with low-level operations—they can affect system stability or data integrity.
• Double-check file paths and IDs before running destructive or irreversible commands.
• Use fsutil primarily for diagnostics and automation; GUI tools are safer for routine tasks.

Common fsutil Commands at a Glance

Using fsutil gives you granular control over Windows file systems, especially useful for scripting, performance tuning, or troubleshooting disk issues. While not needed for everyday use, it’s a valuable tool for admins and power users.

Basically, if you're digging into how files are stored or why space isn’t adding up, fsutil is one of the best places to start.

The above is the detailed content of How to use the fsutil command for file system management in Windows. For more information, please follow other related articles on the PHP Chinese website!