Existing lock /var/run/yum.pid: another copy is running as pid XXXX. Another app is currently holding the yum lock; waiting for it to exit..

When you are searching / installing the RPM and if you ever come across the below exception, 

[root@dhcp-ptp2-10-177-154-84 yum.repos.d]# yum search libaio
Loaded plugins: langpacks
Existing lock /var/run/yum.pid: another copy is running as pid 3339.
Another app is currently holding the yum lock; waiting for it to exit...
  The other application is: PackageKit
    Memory :  25 M RSS (429 MB VSZ)
    Started: Wed Jul  6 14:52:53 2016 - 02:30 ago
    State  : Sleeping, pid: 3339
Another app is currently holding the yum lock; waiting for it to 

Follow the below steps.

cd /var/run/ and you could see a file "yum.pid". Just delete it and try again. Now you can seach / install the RPM.

Not able to install RPM through "yum" utility?

I am trying to search / install rpm through yum utility, when I am searching for it am getting the below exception.

[root@dhcp-blr-kkm-itpark-10fl-10-184-29-195 /]# yum search libaio-devel-0.3.109-12.el7-i686

Loaded plugins: langpacks

http://public-yum.oracle.com/repo/OracleLinux/OL7/UEKR3/x86_64/repodata/repomd.xml: [Errno 14] curl#7 - "Failed connect to public-yum.oracle.com:80; No route to host"

Trying other mirror.

To over come this situation, follow the below steps.

1. Export your Proxy as follows.

[root@dhcp-blr-kkm-itpark-10fl-10-184-29-195 /]# export http_proxy="http://www-XXXXXXXXXX.com:80"

[root@dhcp-blr-kkm-itpark-10fl-10-184-29-195 /]# yum search libaio-devel-0.3.109-12.el7-i686

Loaded plugins: langpacks

ol7_UEKR3                                                                                                                                                                     | 1.2 kB  00:00:00

  2. go to /etc/yum.repos.d/ -> vi public-yum-ol7.repo and edit the below two entries from 0 to 1.

Now try the same.

How to bring your VM in network?

Open your Oracle VM Virtualbox, Select the respective VM -> Right Click, Settings -> Network and enable as follows.

Then logon to your VM, open your browser and give your proxy details.

Now I could connect to the internet.