Quick HOWTO: View contents of RPM without installing it

In Linux, You may wonder what are the files inside a rpm package and you may want to check them before installing it.

You can do this with the below rpm commands:

If the rpm file available locally:
[root@linux_server1 ~]# rpm -qlp telnet-0.17-48.el6.x86_64.rpm
[root@linux_server1 ~]#

[root@linux_server1 ~]# rpm -q -filesbypkg -p numactl-devel-2.0.9-2.el6.x86_64.rpm
numactl-devel             /usr/include/numa.h
numactl-devel             /usr/include/numacompat1.h
numactl-devel             /usr/include/numaif.h
numactl-devel             /usr/lib64/libnuma.a
numactl-devel             /usr/lib64/libnuma.so
[root@linux_server1 ~]#

If you want to check the contents of a rpm located in a remote repository:
[root@linux_server1 ~]# repoquery --list telnet
[root@linux_server1 ~]#

If you want to check the pre installation and post installation scripts which runs while you installing a rpm package.
[root@linux_server1 ~]# rpm -qp --scripts sysstat-9.0.4-33.el6.x86_64.rpm
postinstall scriptlet (using /bin/sh):
/sbin/chkconfig --add sysstat
preuninstall scriptlet (using /bin/sh):
if [ "$1" = 0 ]; then
  # Remove sa logs if removing sysstat completely
  rm -f /var/log/sa/*
  # Remove service
  /sbin/chkconfig --del sysstat
[root@linux_server1 ~]#

If the rpm is already installed, you can use same commands without passing the arguement "-p".

rpm -ql sysstat-9.0.4-33.el6.x86_64
rpm -q --scripts sysstat-9.0.4-33.el6.x86_64

If you want to extract the rpm contents without installing it.
root@linux_server1~]# rpm2cpio telnet-0.17-48.el6.x86_64.rpm | cpio -idmv
220 blocks

Quick HOWTO: Pacemaker Cluster on Redhat Linux - Enable Web GUI Interface

You will notice that your PCS web interface is not working after your pacemaker cluster installation. Because it is not enabled by default. Here is the steps to enable it.

cd /usr/lib/pcsd
vi pcsd.rb
search for "DISABLE_GUI=true"
edit that line to "DISABLE_GUI=false"
service pcsd restart

Now you will be able to access the pacemaker web interface as below: