Moodle: Failed write to disk problem

"Failed to write file to disk"


I've been experience the same problem in wordpress before. 
It was caused by temp folder full. So user failed to upload any files to the system.


Solution:

1. Check your temp folder in moodle
   Eg: /mnt/data/moodle/moodledata/temp/backup/
2. Delete the temp content inside this folder
3. Try upload file to system
4. Upload function should be ok by now.

Good luck!