Andy's Wiki

Me (a few years ago now) Welcome, I'm Andy and this is my wiki.

I've published a collection of short original Debian HOWTOs. These are derived from notes I've taken during my professional life as a linux systems admin and are server orientated.

I'm also in the process of documenting several years work developing Debian Clusters for high-availability, load-balanced networks, and my experiences deploying these in a professional environment.

I have three blogs: Andy's Daily Blog, Andy's Daily Videos, Andy's Science Notes.

For friends and family I have a Photo Album and you can find contact details on Profile.

Fuchsia, from Marvin Peake's Gormenghast

Less formidable, yet sullen as her mother and as incalculable, is Titus' sister. Sensitive as was her father without his intellect, Fuschia tosses her black flag of hair, bites at her childish underlip, scowls, laughs, broods, is tender, is intemperate, suspicious and credulous all in a day. Her crimson dress inflames grey corridors, or flaring in a sunshaft through high branches makes of the deep green shadows a greeness darker yet, and a darkness greener.

How to load-balance and fail-over with LVS

Disable ARP on nodes

ARP broadcasts are special packets which are recognised by your network's switches and used to associate MAC addresses with IP address. The LVS directors will share a common IP address with each of our nodes, and so in order to avoid confusing the switch we need to disable ARP on the nodes.

To disable ARP place the following lines in /etc/sysctl.conf:

/etc/sysctl.conf

net.ipv4.conf.eth0.arp_ignore=3
net.ipv4.conf.eth0.arp_announce=2

And then reboot, or run the following command to make the change take effect immediately:

sysctl -p /etc/sysctl.conf

You can then check the settings just by outputting the appropriate files in /proc:

cat /proc/sys/net/ipv4/conf/eth0/arp_announce
cat /proc/sys/net/ipv4/conf/eth0/arp_ignore 

If your using Shorewall then you will also need to add arp_ignore=3 to its configuration:

/etc/shorewall/interfaces

net     eth0            detect          dhcp,arp_ignore=3

Article from Andy's Debian HOWTOs (http://www.besy.co.uk/debian/debian)

Notes on Fundamental Interactions

There are four fundamental interactions, as summarised below:

Interaction Associated Charge Mediating Particle Relative Strength Range(m)
Gravitation (universal) Graviton 1 infinite
Electromagnetism Electric Photon 1036 infinite
Weak Nuclear Force Flavour W & Z bosons 1025 10-18
Strong Nuclear Force Colour Gluon 1038 10-15

Note: The electromagnetic and weak nuclear forces have been unified.

 
home.txt · Last modified: 2008/03/28 23:24 by andy · [Old revisions]
Recent changes RSS feed Powered by Debian Powered by PHP Valid XHTML 1.0 Valid CSS Driven by DokuWiki