What Is the Large iNode File in the lost+found Folder on My Mac?

If you’re trying to figure out what’s taking up space on your Mac, you might stumble upon some large files inside a folder called lost+found—particularly, a large one with “iNode” in the name. Is there any way to find out what those files are, and whether they’re safe to delete?

We’ve already explained what the lost+found folder in macOS and Linux is, but there are a few specific things you might want to look out for if you’re on a Mac. For those who don’t know, the lost+found folder is where orphaned files end up. Sometimes files end up outside your directory structure without actually being deleted. If you run First Aid in Disk Utility, your Mac may find such files and put them in the lost+found folder. For whatever reason, macOS installers are often ophaned in this way, and found by Disk Utility later, leaving users with a 5GB file in lost+found that’s uselessly taking up space. Though sometimes they can be other important files too.

Sadly, these files aren’t labeled: they have a name that starts with “iNode” and ends with a series of numbers, and there’s no way to work out what they are from the Finder. If you’re wondering whether your large iNode file is an installer or something else, here’s how to find out.

Identifying What’s Inside an iNode File

First, open the Terminal, which you can find in Applications > Utilities or by using Spotlight. Then, head to the lost+found folder by running this command:

cd lost+found

Next, you can use the ls command to see a list of the files in the folder, then run the file command to identify what’s in these orphaned files. Thankfully, you don’t have to type out the entire file name: just type file iNode, then hit the Tab key on your keyboard. the filename will complete itself automatically if there’s only one file, or give you options if there’s more than one.

When you’ve got a complete command, as shown below, hit “Enter” and you’ll see what kind of file you’re dealing with.

Frequently, on Macs, the file in question is going to be a XAR archive, as the file in my example is. If you’d like to confirm that this file is, in face, a macOS installer, the command xar -t -f followed by the filename will show you what’s inside.

As you can see, the XAR archive in my example contains all of the things a macOS installer contains. This means we can delete it without worrying.

You likely don’t need to worry about files in lost+found in any case. If your system needed them to operate, it’s likely something would already be broken. If your Mac is running fine, and you don’t have any important files missing, deleting the file is probably okay. Still, it’s nice to identify the file before doing so.

If you’re really cautious, consider doing the following three things before deleting any iNode files:

  1. Ensure that your computer is backed up with Time Machine (or any other backup system) just in case.
  2. Move the iNode file to your Trash folder, so you can recover it if necessary.
  3. Restart your Mac. If it boots, and everything seems to be in working order, it’s probably fine to empty the Trash.

If even this makes you nervous, and you don’t have a desperate need for storage capacity, there’s no harm in leaving iNode files exactly where they are. They’re not hurting anything: they’re just taking up space.

Justin Pot is a staff writer for How-To Geek, and a technology enthusiast who lives in Hillsboro, Oregon. Follow him on Twitter and Facebook, if you want. You don't have to.