Fix: mkdir: Cannot Create Directory: File Exists On CIFS

Aug 7, 2025 by Viktoria Ivanova 59 views

Troubleshooting 'mkdir: cannot create directory': File exists Error on CIFS Mount in Arch Linux

Hey guys! Ever run into that super annoying situation where you're trying to create a directory using mkdir, and it throws a "cannot create directory 'your_directory': File exists" error, even though ls -a shows absolutely nothing there? Yeah, it's a head-scratcher, especially when you're dealing with network shares like CIFS mounts in Arch Linux. Let's dive deep into this puzzle and figure out how to solve it. This guide will walk you through the common culprits and solutions, making sure you can get back to smoothly managing your files and directories. We’ll explore everything from permission issues to caching problems, and even those sneaky hidden characters that can sometimes cause chaos.

So, you've got your Arch Linux system all set up, and you're trying to create a new directory on a CIFS (Common Internet File System) mount. CIFS is the go-to protocol for sharing files over a network, especially with Windows-based systems. You've mounted a directory from your NAS (Network Attached Storage) using an entry in your /etc/fstab file, which automatically mounts the share on boot. You’ve even made sure to set those permissions nice and wide with dir_mode=0777, thinking everything should be smooth sailing. But then, BAM! The dreaded mkdir error pops up, telling you the directory already exists. What gives?

The error message "mkdir: cannot create directory 'your_directory': File exists" is your computer's way of saying, "Hey, I think something's already here with that name." But when you run ls -a to list all files and directories (including hidden ones), the directory you're trying to create is nowhere to be seen. This discrepancy is the heart of our mystery. It suggests that there's some kind of disconnect between what your system thinks is there and what's actually visible. This can be due to a variety of reasons, which we’ll delve into.

Okay, let's break down the usual suspects behind this frustrating issue. We'll go through each potential cause, offering clear, actionable solutions to get you back on track. From permission headaches to caching quirks, we've got you covered.

1. Permission Problems

Permission issues are often the first place to look when dealing with CIFS mounts. Even though you've set dir_mode=0777 in your fstab, which should grant everyone full access, there might be underlying permission restrictions on the NAS itself, or your user might not be correctly mapped. Remember, CIFS permissions can be tricky because they involve both the client (your Arch Linux system) and the server (your NAS) sides.

Solution:

Check NAS Permissions: Log into your NAS's web interface and verify the permissions for the shared folder. Make sure that the user account you're using to mount the share has read, write, and execute permissions. Sometimes, the NAS might have its own user management system that needs to be configured separately.
Verify User Mapping: In your fstab entry, you're using uid=my_user and gid=my_group. Ensure that my_user and my_group on your Arch Linux system correspond to a user and group that have the necessary permissions on the NAS. It's crucial that the user ID (UID) and group ID (GID) on your Linux system match the ones recognized by the NAS. If there's a mismatch, the NAS might not grant the correct permissions.
Use forceuid and forcegid: Add forceuid and forcegid options to your fstab entry. This forces the CIFS mount to use the specified UID and GID, which can help bypass permission issues. Your line in /etc/fstab should look something like this:
```
//IP_ADDRESS/path/to/dir    /path/to/local/dir    cifs    uid=my_user,gid=my_group,dir_mode=0777,forceuid,forcegid,...    0 0
```
After making this change, you'll need to unmount and remount the share for the changes to take effect. You can do this using the following commands:
```
sudo umount /path/to/local/dir
sudo mount /path/to/local/dir
```
Check Windows Permissions (if applicable): If your NAS is using Windows file sharing, check the Windows permissions on the shared folder. Windows permissions can sometimes override the CIFS mount options. Ensure that the user account you're using has the appropriate permissions in Windows.

By thoroughly checking and adjusting permissions on both your Arch Linux system and your NAS, you can often resolve the "File exists" error caused by permission restrictions. Remember to unmount and remount the share after making changes to your fstab entry to ensure the new settings are applied.

2. Caching Issues

Sometimes, the issue isn't about actual files existing, but rather your system having a cached idea that they do. CIFS clients use caching to improve performance, but this can lead to inconsistencies between what's displayed and what's really there. If a file or directory was recently deleted or created, the cache might not have caught up yet.

Solution:

Clear the CIFS Cache: The most straightforward solution is to clear the CIFS cache. You can do this by unmounting and remounting the share. This forces the system to refresh its view of the network directory. Run these commands:
```
sudo umount /path/to/local/dir
sudo mount /path/to/local/dir
```
This is like giving your file system a quick reboot, making sure it's seeing the most current state of things.
Use the cache=none Option: To prevent caching issues in the future, you can add the cache=none option to your fstab entry. This tells the CIFS client not to cache file and directory information. Keep in mind that disabling caching can impact performance, especially with frequently accessed files. Your line in /etc/fstab might look like this:
```
//IP_ADDRESS/path/to/dir    /path/to/local/dir    cifs    uid=my_user,gid=my_group,dir_mode=0777,cache=none,...    0 0
```
After adding cache=none, unmount and remount the share to apply the changes. This option ensures that your system always retrieves the latest information from the NAS, but it's a trade-off between accuracy and speed.
Consider actimeo: If you don't want to completely disable caching but still want to reduce the chances of stale cache entries, you can adjust the actimeo mount option. actimeo specifies the time (in seconds) that file and directory attributes are cached. Lowering this value makes the cache update more frequently. For example, setting actimeo=5 will refresh the cache every 5 seconds. Your fstab entry would look like:
```
//IP_ADDRESS/path/to/dir    /path/to/local/dir    cifs    uid=my_user,gid=my_group,dir_mode=0777,actimeo=5,...    0 0
```
Remember to unmount and remount the share after making changes. This approach provides a balance between performance and cache freshness.

By addressing caching issues, you can ensure that your system has an accurate view of the files and directories on your CIFS share, preventing those misleading "File exists" errors.

3. Hidden Characters or Filenames

Sometimes, the issue isn't as straightforward as permissions or caching. There might be hidden characters or unusual filenames causing the problem. These can be remnants of past operations or even accidental creations. They're like those sneaky gremlins that mess with your system behind the scenes.

Solution:

List All Files, Including Hidden Ones: You've already used ls -a, which is a great start. But let's go a step further and use ls -la to see detailed information about each file, including permissions, ownership, and modification times. This can sometimes reveal hidden files or directories with unusual names.
```
ls -la /path/to/local/dir
```
Carefully examine the output for any unexpected entries. Pay special attention to filenames that start with a dot (.), as these are hidden by default. Also, look for any strange characters or spaces in the filenames.
Use find to Locate Hidden Files: The find command is a powerful tool for locating files based on various criteria. You can use it to search for hidden files or directories within your mount point. For example:
```
find /path/to/local/dir -type d -name ".*"
```
This command searches for directories (-type d) with names that start with a dot (-name ".*"). You can adapt this command to search for other patterns or file types.
Check for Whitespace or Special Characters: Hidden whitespace or special characters in filenames can cause issues with mkdir. Try using tab completion in your terminal when typing the directory name. If tab completion adds extra characters or doesn't work as expected, it could indicate a problem with the filename.
Use a GUI File Manager: Sometimes, a graphical file manager can provide a clearer view of the directory contents, especially when dealing with hidden files or unusual filenames. Open your file manager (like Nautilus, Thunar, or Dolphin) and navigate to your mount point. Enable the option to show hidden files (usually found in the view menu or settings). This can help you visually identify any problematic entries.
Remove or Rename Problematic Files: Once you've identified the culprit, you can try removing or renaming it. Be cautious when deleting files, especially if you're unsure of their purpose. If you suspect a hidden file is causing the issue, you can try renaming it to something more manageable or deleting it altogether.

By thoroughly investigating hidden characters and filenames, you can uncover those sneaky issues that might be preventing you from creating new directories. This meticulous approach often reveals the root cause of the problem.

4. Network Connectivity Issues

Sometimes, the problem might not be on your local machine or the NAS, but somewhere in between. Network connectivity issues can lead to intermittent problems with CIFS mounts, including the