cizixs cizixs

Add the following chunk to your existing ISC dhcpd.conf file.

if exists user-class and ( option user-class = "iPXE" ) {
    filename "http://boot.smidsrod.lan/bootstrap.ipxe";
}
else {
    filename "undionly.kpxe";
}

(or see https://gist.github.com/4008017 for a more elaborate setup

Imaging

NodeBox - a nice lib to create images of graph networks
Python Image Library

Scrapping/Parsing

BeautfulSoup - HTML parser
mechanize - automated web browsing

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

What I Wish I'd Known About Equity Before Joining A Unicorn

Disclaimer: This piece is written anonymously. The names of a few particular companies are mentioned, but as common examples only.

This is a short write-up on things that I wish I'd known and considered before joining a private company (aka startup, aka unicorn in some cases). I'm not trying to make the case that you should never join a private company, but the power imbalance between founder and employee is extreme, and that potential candidates would

Macvlan, Ipvlan and 802.1q Trunk Driver Notes

Bash string manipulation cheatsheet

Removal
Delete shortest match of `needle` from front of `haystack`	`${haystack#needle}`

Linux NetFilter, IP Tables and Conntrack Diagrams

IPTABLES TABLES and CHAINS

IPTables has the following 4 built-in tables.

1) Filter Table

Filter is default table for iptables. So, if you don’t define you own table, you’ll be using filter table. Iptables’s filter table has the following built-in chains.

##分布式系统(Distributed System)资料

#####希望转载的朋友，你可以不用联系我．但是一定要保留原文链接，因为这个项目还在继续也在不定期更新．希望看到文章的朋友能够学到更多．

《Reconfigurable Distributed Storage for Dynamic Networks》

介绍:这是一篇介绍在动态网络里面实现分布式系统重构的paper.论文的作者(导师)是MIT读博的时候是做分布式系统的研究的,现在在NUS带学生,不仅仅是分布式系统,还有无线网络.如果感兴趣可以去他的主页了解.

	Latency Comparison Numbers
	--------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns
	Send 1K bytes over 1 Gbps network 10,000 ns 0.01 ms
	Read 4K randomly from SSD* 150,000 ns 0.15 ms

	#!/usr/bin/env bash

	function setup_overlay() {
	ip netns add overlay
	ip netns exec overlay ip li ad dev br0 type bridge
	ip li add dev vxlan42 type vxlan id 42 l2miss l3miss proxy learning dstport 4789
	ip link set vxlan42 netns overlay
	ip netns exec overlay ip li set dev vxlan42 name vxlan1
	ip netns exec overlay ip li set dev vxlan1 master br0
	ip li add dev vetha1 mtu 1450 type veth peer name vetha2 mtu 1450