Sync methods

When you sync mods, BD2 Mod Manager writes all enabled mods into the game’s mod folder:

<game_directory>/BepInEx/plugins/BrownDustX/mods/BD2MM/

Three methods are available. Each one has different performance, disk space, and permission characteristics.

Comparison

	Copy	Symlink	Hardlink
How it works	Duplicates mod files into the game folder	Creates a directory symlink pointing to the staging folder	Creates hardlinks — multiple directory entries for the same file data
Disk space	Uses extra space (full copy)	No extra space	No extra space
Speed	Slower (file I/O for each mod)	Fastest (single filesystem operation)	Fast
Admin rights required	No	Yes (Windows UAC)	No
Drag & Drop in game folder	Yes	No (Windows restriction on symlink targets)	Yes
Works across drives	Yes	Yes	No (hardlinks are per-volume)

Method details

Copy
Symlink
Hardlink

Copy

Copy is the default and safest sync method. BD2 Mod Manager reads every enabled mod from your staging directory and writes a full copy of each file into BD2MM/.Pros:

No administrator rights required
Works on all Windows configurations
Drag & Drop inside the game folder works normally
Works across different drives

Cons:

Slower sync, especially with many or large mods
Doubles disk usage for all enabled mods

Best for: Most users, especially those without administrator access or who want the simplest setup.

Symlink

Symlink creates a directory symlink inside the game folder that points directly to each mod’s folder in the staging directory. No file data is duplicated.Pros:

Near-instant sync regardless of how many mods you have
Zero extra disk space
Changes to mod files in the staging directory are immediately reflected in the game

Cons:

Requires administrator rights on Windows (Windows UAC prompt on each sync)
Drag & Drop into symlinked folders is not available (Windows restriction)

If BD2 Mod Manager cannot create a symlink due to insufficient permissions, the sync will fail with a SymlinkAdminRequired error. Switch to Copy or Hardlink if you do not have administrator access.

Best for: Power users with administrator rights who manage a large number of mods and want the fastest possible sync.

Hardlink

Hardlink creates hardlinks to each mod file. A hardlink is an additional filesystem directory entry that points to the same underlying data as the original file — no data is copied.Pros:

No extra disk space (files share underlying data)
Faster than Copy
No administrator rights required
Drag & Drop works normally

Cons:

Staging directory and game directory must be on the same drive (hardlinks cannot span volumes)
Edits to a hardlinked file affect both the staging copy and the game copy simultaneously

If your staging directory and game directory are on different drives, hardlinks will fail with a HardlinkFailed error. Use Copy instead.

Best for: Users who want space efficiency without the admin requirement, provided both directories are on the same drive.

Choosing a sync method

Check your drive layout

If your staging directory and game directory are on different drives, Hardlink is not available. Use Copy or Symlink.

Check your permissions

If you do not have administrator rights on your Windows account, Symlink is not available. Use Copy or Hardlink.

Consider mod volume and disk space

If you manage many large mods and want fast syncs, prefer Symlink (with admin) or Hardlink (same drive). If disk space is not a concern and you want zero friction, use Copy.

Sync errors

If a sync fails, BD2 Mod Manager reports one of the following errors:

Error	Cause	Resolution
`SymlinkAdminRequired`	Symlink method selected but app lacks admin rights	Run BD2 Mod Manager as administrator, or switch to Copy or Hardlink
`ModPathNotFound`	A mod’s folder in the staging directory does not exist	Reinstall the missing mod or remove it from the mod list
`CopyFailed`	A file could not be copied	Check disk space and file permissions
`SymlinkFailed`	Symlink creation failed for a reason other than permissions	Check that the target path is valid and accessible
`HardlinkFailed`	Hardlink creation failed	Confirm staging and game directories are on the same volume
`DirectoryCreationFailed`	Could not create a directory inside the game folder	Check disk space and write permissions on the game directory
`RemovalFailed`	An existing file or symlink could not be removed during re-sync	Close the game if it is running, then retry

Most sync errors are resolved by ensuring BD2 Mod Manager has write access to the game directory and that the game is not currently running.

Settings

Comparison

Method details

Copy

Symlink

Hardlink

Choosing a sync method

Sync errors

Build docs developers (and LLMs) love

Settings

​Comparison

​Method details

​Copy

​Symlink

​Hardlink

​Choosing a sync method

​Sync errors

Build docs developers (and LLMs) love

Comparison

Method details

Copy

Symlink

Hardlink

Choosing a sync method

Sync errors