The error “errno 28 no space left on device” on your Linux system can indeed be frustrating, especially when it appears that you still have disk space available. Based on your description, it seems you’ve already taken some appropriate steps, such as rebooting and checking for hidden files. However, the fact that your inode usage is at 80% capacity could very well be the culprit. Each file and directory on a Linux system consumes an inode, and when you run out of inodes, you won’t be able to create new files even if you have free disk space. To resolve this, you may consider deleting unnecessary files or directories, particularly in locations that may have lots of small files, such as temporary directories or build directories commonly used in development environments. You can check which directories are consuming the most inodes by using `find /path/to/directory -xdev -printf ‘%h\n’ | sort | uniq -c | sort -n`.

If you’re still facing the issue after addressing inode usage, you should also consider potential permission issues or filesystem errors. Misconfigured permissions sometimes prevent applications from writing to a legitimate location, triggering such errors. You can check permissions on directories, especially those where you’re trying to create or modify files, using the `ls -ld /path/to/directory` command. Additionally, running a filesystem check with `fsck` (if it’s possible while the filesystem is unmounted) could help resolve any underlying issues. If neither of these solutions works, you could also experiment with temporarily moving data to another partition to further diagnose whether the issue is specific to the problematic partition. This troubleshooting approach should hopefully steer you towards resolving the annoyance you’re experiencing.