Existing lock /var/run/yum.pid: another copy is running as pid

▒ yum 사용시 Existing lock /var/run/yum.pid: another copy is running as pid 오류

$ yum install telnet-server

Loaded plugins: rhnplugin, security

This system is not registered with ULN.

ULN support will be disabled.

Existing lock /var/run/yum.pid: another copy is running as pid 4052.

Another app is currently holding the yum lock; waiting for it to exit...

  The other application is: yum

    Memory :  25 M RSS (251 MB VSZ)

    Started: Wed Aug 13 13:20:37 2014 - 11:52 ago

    State  : Traced/Stopped, pid: 4052

Another app is currently holding the yum lock; waiting for it to exit...

  The other application is: yum

    Memory :  25 M RSS (251 MB VSZ)

    Started: Wed Aug 13 13:20:37 2014 - 11:54 ago

    State  : Traced/Stopped, pid: 4052

Another app is currently holding the yum lock; waiting for it to exit...

  The other application is: yum

    Memory :  25 M RSS (251 MB VSZ)

    Started: Wed Aug 13 13:20:37 2014 - 11:56 ago

    State  : Traced/Stopped, pid: 4052

Another app is currently holding the yum lock; waiting for it to exit...

  The other application is: yum

    Memory :  25 M RSS (251 MB VSZ)

    Started: Wed Aug 13 13:20:37 2014 - 11:58 ago

    State  : Traced/Stopped, pid: 4052

^C

$ ps -ef | grep 4052

root      4052  4020  2 13:20 pts/1    00:00:23 /usr/bin/python /usr/bin/yum -y install telnet-server

root      4124  4020  0 13:36 pts/1    00:00:00 grep 4052

$ kill -9 4052

이후 yum install 정상 수행 확인