Changxin Miao polyrabbit

Linux Backup Solutions

I've been looking for the best Linux backup system, and also reading lots of HN comments.

Instead of putting pros and cons of every backup system I'll just list some deal-breakers which would disqualify them.

Also I would like that you, the HN community, would add more deal breakers for these or other backup systems if you know some more and at the same time, if you have data to disprove some of the deal-breakers listed here (benchmarks, info about something being true for older releases but is fixed on newer releases), please share it so that I can edit this list accordingly.

Amanda (comments by sammcj)

It has a lot of management overhead and that's a problem if you don't have time for a full time backup administrator.

检查以下文件夹删除不需要的即可以

~/Library/Logs/ (我全删了,没影响)
~/Library/Caches/xxxxx(使用 DaisyDisk 找到容量比较大的删除. 不会对系统有影响)
~/Library/Caches/com.spotify.client(全删, 正常工作)
~/Library/Caches/Google/chrome (全删, 正常工作)
/Applications/Google Chrome/Contents/Versions/ (只保留最新的那个文件夹, 其他的删除, 正常工作)
~/Library/Developer/Xcode/DerivedData/ (全删, 正常工作.)

工具:

DaisyDisk 使用试用版即可,可直观查看文件(夹)大小.

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

	#include <iostream>

	// This is a rewrite of the technique showed here:
	// http://bloglitb.blogspot.com/2010/07/access-to-private-members-thats-easy.html
	// https://gist.github.com/dabrahams/1528856

	// Generate a static data member of type Stub::type in which to store
	// the address of a private member. It is crucial that Stub does not
	// depend on the /value/ of the the stored address in any way so that
	// we can access it from ordinary code without directly touching

	/*
	# Copyright H. Watanabe 2017
	# Distributed under the Boost Software License, Version 1.0.
	# (See accompanying file LICENSE_1_0.txt or copy at
	# http://www.boost.org/LICENSE_1_0.txt)
	*/

	#include <iostream>
	#include <vector>
	#include <map>

	// To the extent possible under law, the Yawning Angel has waived all copyright
	// and related or neighboring rights to orhttp_example, using the creative
	// commons "cc0" public domain dedication. See LICENSE or
	// <http://creativecommons.org/publicdomain/zero/1.0/> for full details.

	package main

	import (
	// Things needed by the actual interface.
	"golang.org/x/net/proxy"

	int
	binary_search_first_position(int *A, int n, int target) {
	int end[2] = { -1, n };
	while (end[0] + 1 < end[1]) {
	int mid = (end[0] + end[1]) / 2;
	int sign = (unsigned)(A[mid] - target) >> 31;
	end[1-sign] = mid;
	}
	int high = end[1];
	if (high >= n \|\| A[high] != target)

	#!/usr/bin/env bash
	# MIT © Sindre Sorhus - sindresorhus.com

	# git hook to run a command after `git pull` if a specified file was changed
	# Run `chmod +x post-merge` to make it executable then put it into `.git/hooks/`.

	changed_files="$(git diff-tree -r --name-only --no-commit-id ORIG_HEAD HEAD)"

	check_run() {
	echo "$changed_files" \| grep --quiet "$1" && eval "$2"

	#!/usr/bin/env python

	"""Simple HTTP Server With Upload.

	This module builds on BaseHTTPServer by implementing the standard GET
	and HEAD requests in a fairly straightforward manner.

	"""

	#!/bin/bash

	if [ "$1" = "-h" -o "$1" = "--help" -o -z "$1" ]; then cat <<EOF
	appify v3.0.1 for Mac OS X - http://mths.be/appify
	Creates the simplest possible Mac app from a shell script.

	Appify takes a shell script as its first argument:

	`basename "$0"` my-script.sh