I believe that some linux users, especially system administrators encountered this problem and get the message after issue the yum command:
Existing lock /var/run/yum.pid: another copy is running as pid [pid number]. Another app is currently holding the yum lock; waiting for it to exit...
Example :
[root@server /]# yum install [service name]
Loaded plugins: fastestmirror
Existing lock /var/run/yum.pid: another copy is running as pid 20360.
Another app is currently holding the yum lock; waiting for it to exit...
The other application is: yum
Memory : 19 M RSS (396 MB VSZ)
Started: Sun Mar 6 21:06:51 2011 - 00:29 ago
State : Traced/Stopped, pid: 20360
Please hit ctrl-c; that’s the key combination to kill any currently running process in a bash shell or terminal.
Exiting on user cancel.
Solution 1:
To remove the pid, please issue command rm -f and follow with yum.pid path and [pid number]
[root@server /]# rm -f /var/run/yum.pid 20360
Solution 2:
Find out what is the locking up yum by running:
[root@server /]# ps aux | grep yum
Please take note on the [pid number] of the process and run this command to kill the process:
[root@server /]# kill -9 [insert pid]