When I'm trying to move/remove some files in Finder, but I've got this message:

Some of the items you are moving are in use by another application. Moving the items can cause problems with the application using them. Are you sure you want to move these items? [Stop] [Continue]

And these files are greyed out.

When I'm trying to copy the files, it's saying:

One or more items in “X” can’t be changed because they are in use.

Similar situation happens when I'm trying to empty my Trash or eject my disk and something is preventing to do it.

So I'm looking for software which can determine what process is holding my files open or blocking ejection of a disk.

1 Answer 1


Here are few OSX build-in apps which can determine file changes:

  • fs_usage (part of FSEvents), see man fs_usage for help.

    Example usage:

    sudo fs_usage | grep my_file
  • opensnoop (DTrace script) - snoop file opens as they occur.

    Example usage:

    $ sudo opensnoop -ve
    $ sudo opensnoop -ve | grep Scores

Here are 3rd party apps:

  • What's Keeping Me by HAMSoft Engineering

    This tool was made to help when you have trouble emptying the trash or ejecting a disk, but it can check for file names as well.

    What's Keeping Me? screenshot

  • fseventer by fernlightning

    Provides a graphical representation of the file activity.

    fseventer screenshot

    10.10 Yosemite is classified as unsupported till further notice.

  • WhatsOpen by Agathezol's Projects

    It's for MacOS 10.5 or greater (tested on 10.6 and 10.7) and it is available in the US Mac AppStore (but not for UK).

    WhatsOpen is a MacOSX utility designed to aid you in determining what is holding your files open. There is a common OSX error when trying to eject removable media relating to files being in use. Often times your files are in use by Spotlight or some other internal system and you don’t even know what program to kill to free up the files and allow the media to eject. This utility makes that a snap. It also provides many other administrative features you may find useful.

  • FileMon

  • FS Spy


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