The df and du commands provide different system information and I can not write to a partition that df says is 100% full. Which is correct and why does the system not allow any data writes to this partition?

Issue

• Unable to find which files are consuming disk space.
• Why is there a mismatch between df and du outputs?

• The df and du commands provide different information and I can not write to a partition that df says is 100% full. Which is correct and why does the system not allow any data writes to this partition?

• df says that the system is out of disk space on one of my partitions, but du shows plenty of space left. For example:

  # df -h
  Filesystem            Size  Used Avail Use% Mounted on
  /dev/md1              7.9G  7.8G     0 100% /var
  
  # du -sh /var
  50M     var