After configuring the primary LVS router, there are several
configuration files that must be copied to the backup LVS router
before you start the cluster.
These files include:
-
/etc/sysconfig/ha/lvs.cf — the
configuration file for the LVS routers.
-
/etc/sysctl — the configuration
file that, among other things, turns on packet forwarding in the
kernel.
-
/etc/sysconfig/iptables — If you
are using firewall marks, you should synchronize one of these files
based on which network packet filter you are using.
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Important |
| |
The /etc/sysctl.conf and /etc/sysconfig/iptables files do not change when you configure the cluster using the
Piranha Configuration Tool.
|
Anytime the LVS configuration file, /etc/sysconfig/ha/lvs.cf, is created or
updated, you must copy it to the backup LVS router node.
 |
Warning |
| |
Both the active and backup LVS router nodes must have identical
lvs.cf files. Mismatched LVS
configuration files between the LVS router nodes can prevent
failover.
|
The best way to do this is to use the scp command.
Issue the following command as the root user from the primary
LVS router to sync the lvs.cf files
between the router nodes:
scp /etc/sysconfig/ha/lvs.cf n.n.n.n:/etc/sysconfig/ha/lvs.cf
|
In the above command, replace n.n.n.n with the real IP address of the backup
LVS router.
The sysctl file is only modified once
in most situations. This file is read at boot time and tells the
kernel to turn on packet forwarding.
|
Important |
| |
If you are not sure whether or not packet forwarding is enabled
in the kernel, see Section 8.5
Turning on Packet Forwarding for instructions on how to
check and, if necessary, enable this key functionality.
|
If you are using iptables, you will
need to synchronize the appropriate configuration file on the
backup LVS router.
If you alter the any network packet filter rules, enter the
following command as root from the primary LVS router:
scp /etc/sysconfig/iptables n.n.n.n:/etc/sysconfig/
|
In the above command, replace n.n.n.n with the real IP address of the backup
LVS router.
Next either open an ssh session to the
backup router or log into the machine as root and type the
following command:
/sbin/service iptables restart
|
Once you have copied these files over to the backup router and
started the appropriate services (see Section 8.1 Configuring
Services on the LVS Routers for more on this topic) you are
ready to start the cluster.
