Rodrigo Barbosa wrote:

On Thu, Jan 26, 2006 at 04:15:59PM -0500, Bowie Bailey wrote:

...

I am trying to configure load balancing for a couple of CentOS4 servers. In order to make it work, I need to add a hidden networking device on each server with the virtual IP. I found the following instructions on linuxvirtualserver.org for doing this, but they don't work.

echo 1 > /proc/sys/net/ipv4/ip_forward
ifconfig dummy0 0.0.0.0 up
echo 1 > /proc/sys/net/ipv4/conf/all/hidden
echo 1 > /proc/sys/net/ipv4/conf/dummy0/hidden
ifconfig dummy0:0 172.26.20.110 up

When I try to write to /proc/sys/net/ipv4/conf/all/hidden, the system refuses to let me create the file. I'm logged in as root, so why am I having permission problems?

Also, I believe these instructions are for 2.2 or 2.4 kernels. Have things changed with 2.6?

No, things are exactly the same. Meaning that LVS is a separated patch that is not included either on the stock kernel or the RHEL one.

If you really want to use LVS, you will have to apply the patch.

Hmm... I saw a reference to a kernel patch, but I thought the patch was for the server. I am actually not using a Linux LVS server, I am using a Foundry ServerIron to do the load balancing. It works great for standard balancing, but now I need to do direct routing to balance two CentOS4 servers. The instructions that came with the ServerIron just gave a single ifconfig command to set it up (which royally screwed up the networking).

Do I need to install the kernel patch on these machines? And why would that affect the permissions problem I was seeing? As root, I should be able to create a file in any directory. It may not do what I expect if the functionality is not in the kernel, but I should be able to create the file.