View source for Mini Mini Howto

== Mini-Mini-Howto ==

This howto describes a quick way to get up and going with LVS.

== Instructions ==

Start from a precompiled Linux distribution.  I was using a combination of Fedora Core 4 and Fedora Core 6, but this should work with any recent version of Linux.

The following will set up the [[real server]]s (192.168.1.100 and 192.168.1.101) to accept data from the [[load balancer]] (192.168.1.5) for VIP 192.168.1.10.  I put it into a shell script and added that script to /etc/rc.d/rc.local on real servers.

 echo 1 > /proc/sys/net/ipv4/conf/eth0/arp_ignore
 echo 2 > /proc/sys/net/ipv4/conf/eth0/arp_announce
 echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
 echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
 
 ifconfig lo:0 192.168.1.10 netmask 255.255.255.255 broadcast 192.168.1.10 up

One time setup on the load balancer:

 rpm -U /net/shauna/usr/local/share/RPMS/4/ipvsadm-1.24-7.x86_64.rpm

I put the following script on the load balancer, again referenced in /etc/rc.d/rc.local

 ifconfig eth0:0 192.168.1.10 netmask 255.255.255.255 broadcast 192.168.1.10 up
 ipvsadm --clear
 ipvsadm --add-service --tcp-service 192.168.1.10:80 --scheduler rr
 ipvsadm --add-server --tcp-service 192.168.1.10:80 --real-server 192.168.1.100:80 --gatewaying
 ipvsadm --add-server --tcp-service 192.168.1.10:80 --real-server 192.168.1.101:80 --gatewaying

That’s all it took.  I didn’t recompile anything.  My firewall treats 192.168.1.10, the VIP, just like an ordinary machine.  Inside the firewall I have a standard switch.  Aside from the firewall, all of the machines are using only one NIC and one subnet.

Note: the [[LVS/DR]] load balancing method is used in the above example.

== Rationale ==

Several years ago I set up an LVS.  Recently I did it again.  Because of changes in the 2.6 kernel, it was a whole lot easier this time.  It was almost trivial.  Unfortunately, it took me a long time to dig through the documentation to what I needed.

All of this information was available on Google, but it was hiding.  I can appreciate the older documentation – as I said I worked with this software a long time ago – but some of it has little or no value.  How many people, for example, need to use an old version of the kernel?  There may be a place for that information, but it should not be the first thing that a potential user sees.

[[Category:LVS Handbook]]