2.2. Cluster Software Installation

Go to the terminal window you just opened and switch to the super user (aka. "root") account with the su command. You will need to supply the password you entered earlier during the installation process.

[beekhof@pcmk-1 ~]$ su -
Password:
[root@pcmk-1 ~]#

Note

Note that the username (the text before the @ symbol) now indicates we’re running as the super user “root”.

[root@pcmk-1 ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
    link/ether 00:0c:29:6f:e1:58 brd ff:ff:ff:ff:ff:ff
    inet 192.168.9.41/24 brd 192.168.9.255 scope global eth0
    inet6 ::20c:29ff:fe6f:e158/64 scope global dynamic 
       valid_lft 2591667sec preferred_lft 604467sec
    inet6 2002:57ae:43fc:0:20c:29ff:fe6f:e158/64 scope global dynamic 
       valid_lft 2591990sec preferred_lft 604790sec
    inet6 fe80::20c:29ff:fe6f:e158/64 scope link 
       valid_lft forever preferred_lft forever
[root@pcmk-1 ~]# ping -c 1 www.google.com
PING www.l.google.com (74.125.39.99) 56(84) bytes of data.
64 bytes from fx-in-f99.1e100.net (74.125.39.99): icmp_seq=1 ttl=56 time=16.7 ms

--- www.l.google.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 20ms
rtt min/avg/max/mdev = 16.713/16.713/16.713/0.000 ms
[root@pcmk-1 ~]# /sbin/chkconfig network on
[root@pcmk-1 ~]#

2.2.1. Security Shortcuts

To simplify this guide and focus on the aspects directly connected to clustering, we will now disable the machine’s firewall and SELinux installation. Both of these actions create significant security issues and should not be performed on machines that will be exposed to the outside world.

Important

TODO: Create an Appendix that deals with (at least) re-enabling the firewall.

[root@pcmk-1 ~]# sed -i.bak "s/SELINUX=enforcing/SELINUX=permissive/g" /etc/selinux/config
[root@pcmk-1 ~]# /sbin/chkconfig --del iptables
[root@pcmk-1 ~]# service iptables stop
iptables: Flushing firewall rules:                         [  OK  ]
iptables: Setting chains to policy ACCEPT: filter          [  OK  ]
iptables: Unloading modules:                               [  OK  ]

Important

You will need to reboot for the SELinux changes to take effect. Otherwise you will see something like this when you start corosync:

May  4 19:30:54 pcmk-1 setroubleshoot: SELinux is preventing /usr/sbin/corosync "getattr" access on /. For complete SELinux messages. run sealert -l 6e0d4384-638e-4d55-9aaf-7dac011f29c1
May  4 19:30:54 pcmk-1 setroubleshoot: SELinux is preventing /usr/sbin/corosync "getattr" access on /. For complete SELinux messages. run sealert -l 6e0d4384-638e-4d55-9aaf-7dac011f29c1