VMWare Linux parameter

/etc/sysctl.conf

# vm.swappiness = 0	The kernel will swap only to avoid an out of memory condition.
vm.swappiness = 0

# TCP SYN Flood Protection
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 4096
net.ipv4.tcp_synack_retries = 3

Pinning kernel to 2.6 for ESX 4.1

Create /etc/apt/preferences.d/linux-image with this content:

Package: linux-image-server linux-server linux-headers-server
Pin: version 2.6.*
Pin-Priority: 1000