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.
 | 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.
