xauth: unable to open tmp file and unable to write authority file error messages

/usr/X11R6/bin/xauth: unable to open tmp file “/home/user/.Xauthority-n”
/usr/X11R6/bin/xauth: unable to write authority file /home/user/.Xauthority-

/usr/X11R6/bin/xauth: error in locking authority file /home/user/.Xauthority

This error usually happens when you are not able to create a file on your home directory

user@linux:~ $ touch /home/user/.Xauthority
touch: cannot touch `/home/user/.Xauthority’: No space left on device

Checking the space utilization on this filesystem we see that we have some space left

root@linux:~ # df -h /home
Filesystem Size Used Avail Use% Mounted on
6.9G 4.8G 1.9G 73% /home

This error was solved when I deleted some files on this filesystem. There were a lot of small log files that occupied all the inodes on the filesystem

root@linux:~ # df -i /home
Filesystem Inodes IUsed IFree IUse% Mounted on
917504 917504 0 100% /home