좀비 프로세스(Zombie Process)

[root@localhost usr]# ps -ef | grep -i httpd
root      5681     1  0  2015 ?        00:02:31 /usr/bin/httpd
nobody   26720     1  0  2015 ?        00:00:00 /usr/local/apache/bin/httpd -DSSL
nobody   29354     1  0  2015 ?        00:00:00 /usr/local/apache/bin/httpd -DSSL
nobody   29363     1  0  2015 ?        00:00:00 /usr/local/apache/bin/httpd -DSSL
nobody   32225     1  0  2015 ?        00:00:00 /usr/local/apache/bin/httpd -DSSL
root      5198     1  0 Feb24 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22321  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22322  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22323  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22324  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22325  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22331  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22334  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22335  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22339  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22340  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22341  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22342  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22350  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22351  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22352  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22353  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22354  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22355  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22358  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22359  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22370  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22371  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22372  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22373  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22375  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22376  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22379  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22380  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22382  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22386  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22388  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22392  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22393  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22394  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22395  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22399  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22406  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22407  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22408  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22427  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22428  5198  0 06:54 ?        00:00:00 [httpd] <defunct>
nobody   22429  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22430  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22431  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22432  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22433  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22434  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22435  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22437  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22438  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22439  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
nobody   22440  5198  0 06:54 ?        00:00:00 /usr/local/apache2/bin/httpd -k start
root     22442 22252  0 06:54 pts/0    00:00:00 grep -i httpd
[root@localhost usr]#

이번의 경우는 디스크가 가득 차서 발생한 문제로 사용하지 않는 로그나 파일들을 삭제 하여 해결 됨.