linux - cannot use any yum command: no space left on device

if i use any yum command, i get

Loaded plugins: fastestmirror
Traceback (most recent call last):

  File "/usr/bin/yum", line 29, in 
    yummain.user_main(sys.argv[1:], exit_code=True)
  File "/usr/share/yum-cli/yummain.py", line 285, in user_main
    errcode = main(args)
  File "/usr/share/yum-cli/yummain.py", line 114, in main
    base.doLock()
  File "/usr/lib/python2.6/site-packages/yum/__init__.py", line 1791, in doLock
    while not self._lock(lockfile, mypid, 0644):
  File "/usr/lib/python2.6/site-packages/yum/__init__.py", line 1861, in _lock
    os.write(fd, contents)

OSError: [Errno 28] No space left on device

If i use the top command i see this. If i use the df -h i see this.

Is it yum error? python error? or what?

EDIT

the output of find / -size +1G is

/var/log/squid/access.log-20130317
find: File system loop detected; `/var/named/chroot/var/named' is part of the same file system loop as /var/named'.

find: /proc/31495/task/31495/fd/5': No such file or
directory find:/proc/31495/task/31495/fdinfo/5': No such file or
directory find: `/proc/31495/fd/5': No such file or directory find:

/proc/31495/fdinfo/5': No such file or directory

Answer

Looks like / is full

While you have almost 500GB in /home.

You might wanna reallocate some more space to / for system use.

Also, check /var/log as it resides on /

It is very possible you have some huge log files that could be pruned to clear up some space. 10G isnt much, but can be enough.