Existing lock /var/run/yum.pid: yum锁定

[root@instructor Packages]#  yum install elfutils-libelf-devel
Loaded plugins: refresh-packagekit, rhnplugin
This system is not registered with RHN.
RHN support will be disabled.
Existing lock /var/run/yum.pid: another copy is running as pid 2069.
Another app is currently holding the yum lock; waiting for it to exit...
  The other application is: yum
    Memory : 135 M RSS (438 MB VSZ)
    Started: Sun Oct 21 05:15:24 2012 - 15:36 ago
    State  : Traced/Stopped, pid: 2069
Another app is currently holding the yum lock; waiting for it to exit...
  The other application is: yum
    Memory : 135 M RSS (438 MB VSZ)
    Started: Sun Oct 21 05:15:24 2012 - 15:38 ago
    State  : Traced/Stopped, pid: 2069
Another app is currently holding the yum lock; waiting for it to exit...
  The other application is: yum
    Memory : 135 M RSS (438 MB VSZ)
    Started: Sun Oct 21 05:15:24 2012 - 15:40 ago
    State  : Traced/Stopped, pid: 2069
/var/run/yum.pid^C

Exiting on user cancel.

#------------------------以上yum锁定
#-----------------------应清楚yum.pid

[root@instructor Packages]# rm /var/run/yum.pid
rm: remove regular file `/var/run/yum.pid'? y
[root@instructor Packages]#  yum install elfutils-libelf-devel
Loaded plugins: refresh-packagekit, rhnplugin
This system is not registered with RHN.
RHN support will be disabled.
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package elfutils-libelf-devel.x86_64 0:0.148-1.el6 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

=============================================================================================================
 Package                           Arch               Version                 Repository                Size
=============================================================================================================
Installing:
 elfutils-libelf-devel             x86_64             0.148-1.el6             InstallMedia              30 k

Transaction Summary
=============================================================================================================
Install       1 Package(s)
Upgrade       0 Package(s)

Total download size: 30 k
Installed size: 31 k
Is this ok [y/N]: y