No space left in device error despite being empty

2 min read 28-10-2024

the ifix

No space left in device error despite being empty

The "No space left on device" error can be particularly frustrating, especially when it seems that your storage should be empty. This issue can arise in various computing environments, including Linux systems, which often utilize both physical and logical storage units. Below, we explore the possible causes and solutions for this error, providing a clear understanding of why it might occur even when space appears to be available.

The Problem Scenario

Consider this scenario: You're attempting to save a file or install an application on your computer. To your surprise, you receive an error message stating, "No space left on device," even though you have checked your storage and it appears empty. Here is a snippet of code that could represent the error when trying to save a file:

$ touch myfile.txt
bash: myfile.txt: No space left on device

Why Does This Happen?

Inode Exhaustion: Every file and directory on a Linux file system is represented by an inode, which stores metadata about files. Even if the total storage is not fully utilized, if you have run out of inodes, you will encounter the "No space left on device" error. You can check inode usage with the following command:
```
df -i
```
If the output shows 100% inode usage, it indicates that you need to delete some files or directories to free up inodes.
Deleted Files Still Open: Sometimes, files that are deleted may still be held open by processes. This means they are not yet removed from disk space. Use the lsof command to find such files:
```
lsof | grep deleted
```
Closing the applications or processes holding these files will free up the space.
File System Corruption: Occasionally, the file system may report that it has space available when it does not due to corruption. Running a file system check (using fsck) can help resolve such issues. Be cautious and ensure you do this when the system is unmounted or in maintenance mode.
Hidden Files and Folders: Some files may be hidden from view due to permissions or settings. Use the du command to check disk usage by directory, including hidden files:
```
du -sh *
```
This will provide a more accurate picture of where your storage space is being consumed.

Practical Solutions

Clear Cache and Temporary Files: Regularly clean up cache and temporary files that can accumulate over time. Use commands like apt-get clean for package manager caches or rm -rf /tmp/* for temporary files.
Uninstall Unused Applications: Remove applications that you no longer use. This action can help clear up both storage space and inodes.
Increase Storage: If you consistently face storage issues, consider upgrading your hard drive or moving to external storage solutions, such as cloud services or external hard drives.
Monitor Disk Usage: Regularly monitor your disk space and inode usage with commands like df -h and df -i. Keeping tabs on your storage can help you avoid running into this issue in the future.

Conclusion

The "No space left on device" error can occur unexpectedly and can be caused by various factors, including inode exhaustion and file system issues. Understanding these causes and employing practical solutions can help you resolve the issue effectively.

Useful Resources

By maintaining awareness of your storage and employing good file management practices, you can avoid the frustrations of unexpected storage issues.