What Are Reparse Records? All You Need To Know

Have you ever thought about What Are Reparse Records? Despite the fact that it is not a new Windows 7 feature, it is a good time to try it out. Within your file system, Reparse Records create Reparse Points.

Reparse Points are an intriguing feature of NTFS that allows a file to be tagged with data that causes a program (an FS Filter, similar to a driver) to be run every time the file is accessed.

They’re only used a few times, mostly to make symlinks in Windows (using the mklink command) and for volume mount points (this is an obscure feature of Windows that allows you to mount a device as a folder in another device, somewhat like the UNIX file system). A standard Windows installation will include a number of them, which will be configured by the installer.

What Are Reparse Records?

Reparse Points are an NTFS feature that gives file system filter drivers a way to intercept and maybe alter file access requests. They supply the engine that drives a number of additional NTFS features, including mount points for volume, junctions in directories, and connections with symbols.

Reparse Point Tags

Each Reparse Point contains an identifying tag that allows you to quickly distinguish between different types of reparse points without having to inspect the reparse point’s user-defined data.

The system employs a set of predefined tags as well as a collection of tags that are exclusive to Microsoft. The procedure fails if you utilize any of the reserved tags when setting a reparse point.

Tags that aren’t in these ranges aren’t reserved and can be used in your application. When you create a reparse point, you must first tag the data that will be stored there.

A new set operation fails if the new data tag does not match the old data after the reparse point has been established. The set action overwrites the existing reparse point if the tags match.

Reparse Point Operations

Call the Get Volume Information function and look at the FILE SUPPORTS REPARSE POINTS bit flag to see if a file system supports reparse points. Set, change, obtain, and remove reparse points using the Device Io Control method. The reparse point procedures that Device Io Control can execute are listed in the table below.

If you’re changing, getting, or deleting a reparse point, you must use the same reparse tag that’s in the file in the action. Otherwise, ERROR REPARSE TAG MISMATCH will occur, and the operation will fail. You must additionally mention the reparse GUID in the operation that is contained in the file if you are updating or deleting a reparse point.

Otherwise, ERROR REPARSE ATTRIBUTE CONFLICT will occur, and the operation will fail. Use the Get File Attributes function to see if a file or directory contains a reparse point. The FILE ATTRIBUTE REPARSE POINT attribute is set if the file or directory has an associated reparse point.

Call Create File with FILE FLAG OPEN REPARSE POINT to overwrite an existing reparse point without having a handle to the file or directory. This flag enables you to open the file regardless of whether the associated file system filter is installed and operational.

Reparse Points

Because reparse points enable file system behavior that differs from what most Windows developers are used to, understanding these behaviors while designing file-manipulation apps is critical to building strong and dependable applications that use file systems that support reparse points.

The degree of these concerns will be determined by the reparse point’s unique implementation and associated file system filter behavior, which can be user-defined.

EA Records 

Extended Attribute records are EA Records. They’re an NTFS feature that allows you can store custom additional metadata alongside a file (metadata that is not interpretable to the file system). EA records are an esoteric feature of NTFS that is rarely used, but having a few of them doesn’t mean you’re file system is broken.

EA records were designed to allow the emulation of OS/2, an early Microsoft operating system that is still utilized in certain legacy systems, as an intriguing side note (support officially ended in 2006). According to Wikipedia, EA records are used by some Windows POSIX layers to store UNIX permissions information.

What Are Reparse Records Processed?

NTFS’s support for Reparse Points allows filter drivers in the file system to modify an access request for a file potentially. The mechanism they give is the driving force behind a number of other NTFS features.

Are Reparse Records Bad?

No! They are not bad.

What Is A Reparse Point?

Reparse points are NTFS file system objects with user-defined data. They extend I/O functionality. Directories and volume mount points. File system filter driver special files.

Conclusion

Hopefully, you now understand What Are Reparse Records? how they are handled as well as the CHKDSK command. This task is now simple to complete on your own. If you have any further questions or require expert assistance, please contact us using the form below.

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