[root@xuegod60 ~]# yum clean all
Loaded plugins: product-id, refresh-packagekit, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Existing lock /var/run/yum.pid: another copy is running as pid 3670.
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit.
……
[root@xuegod60 ~]# ps -aux | grep yum
Warning: bad syntax, perhaps a bogus '-'? See /usr/share/doc/procps-3.2.8/FAQ
root 3670 0.0 0.0 0 0 ? Z 14:27 0:01 [yumBackend.py] <defunct>
root 10595 0.0 0.0 103252 828 pts/0 R+ 15:20 0:00 grep yum
[root@xuegod60 ~]# kill -s 9 3670
[root@xuegod60 ~]# ls /var/run/yum.pid
/var/run/yum.pid
[root@xuegod60 ~]# vim !$
vim /var/run/yum.pid
[root@xuegod60 ~]# rm -rf !$
rm -rf /var/run/yum.pid
[root@xuegod60 ~]# ls !$
ls /var/run/yum.pid
ls: cannot access /var/run/yum.pid: No such file or directory
[root@xuegod60 ~]# yum clean all
Loaded plugins: product-id, refresh-packagekit, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Cleaning repos: epel rhel-source
Cleaning up Everything
现在可以了