Appendix III. How to Backup

1) Basic

• see Backup your work - Basic in Getting Started.

2) Advanced

(1) Backup your code with GitHub in Terminal

• Setup

  • set up ssh-key (optinal)

  • add a setting file: ~/.gitconfig

[user] 
email =[[e-mail]]
name = Shared

• Clone/Download an existed repository on github

git clone [e-mail]:lulab/RNAfinder_Server.git
git clone https://github.com/xug15/test.git

• Create a new repository

echo "# test" >> README.md 
git init 
git add README.md 
git commit -m "first commit" 
git remote add origin https://github.com/xug15/test.git 
git push -u origin master

• Sync local files with github repo

Pull (update):

git pull origin master
git log -n 2 # look at the last two log entries.

Add:

git add exmaples/
git commit -m ‘20190705v1’
git push origin

Change:

git commit -m ‘20190705v1’
git push origin

Remove:

git rm *.file
git commit -m ‘20190705v1’
git push origin

Tips: the bash script to sync a github repo:

time=`date`
echo $time
git add -u .
git add *
git commit -m '$time'
git push origin master

(2) Backup data using rsync and crontab

(2.1) Setup ssh key (optional)

• (a) Generate SSH key

ssh-keygen -t rsa -b 2048

• (b) Copy your keys to the target server

ssh-copy-id user@server_ip    #if port add: -p 2200

上述操作后，通过ssh到remote server时就可以无需输入密码了，因此下面的步骤也可以在无人值守的时候自动运行。

但如果下面的步骤中你无需登录remote server, 就无需setup ssh key。

(2.2) Prepare a backup script with rsync

• (a) First you need to prepare some backup dirs

mkdir /home/john/backup_local    # prepare a backup dir for some local files
mkdir /home/john/backup_remote   # prepare a backup dir for some remote files

• (b) Then, write a back up script, for example : ~/backup.sh

#!/bin/bash

#0. Define the parameters of rsync
RSYNC="rsync --stats  --compress --recursive --times --perms --links --delete --max-size=100M --exclude-from=/home/john/excluded_file_list.txt"

#A. Local backup  
echo "1. Backup of /home/john/data start at:"
date
$RSYNC /home/john/data/  /home/john/backup_local/
echo "Backup end at:"
date

#B. Remote backup 
echo "2. Backup 166.178.56.20:/home/lulab/john/data/ start at:"
date
$RSYNC john@166.178.56.20:/home/lulab/john/data/ /home/john/backup_remote/
echo "Backup end at:"
date

• (c) Last, make your backup.sh excutable

chmod +x ~/backup.sh

Parameters of rsync (use man rsync to see more details):

Parameter	Mean
-a:	以递归方式传输文件
--delete:	删除那些接收端还有而发送端已经不存在的文件
-q:	精简输出模式
-z:	在传输文件时进行压缩处理
-H:	保持硬链接文件
-t:	对比两边文件的时间戳和文件大小.如果一致，则就认为两边文件一样，对此文件就不再采取更新动作了
-I:	挨个文件去发起数据同步
--port=PORT:	端口号

(2.3) Schedule the back tasks with crontab

crontab是Linux中用来定期执行程序的命令, 你可以使用 在线crontab生成器，也可以按如下方式自己编辑：

• 打开crontab编辑器：

crontab -e

• 加入以下行：

# minute hour day_in_month month day_in_week command
15 3 * * * /home/john/backup.sh > /home/john/backup.log

Linux将通过crontab定时运行上述命令, 具体定义如下：

Column	Mean
Column 1:	Minutes 0 to 59
Column 2:	Hours 0 to 23 (0 means midnight)
Column 3:	Day 1 to 31
Column 4:	Months 1~12
Column 5:	Week 0 to 7 (0 and 7 for Sunday)
Column 6:	Command to run

(3) More Reading for advanced users

• 《鸟哥的Linux私房菜-基础学习篇》 (25章推荐章节)

  Linux 推荐章节：

  • 第25章 LINUX备份策略: 25.2.2完整备份的差异备份; 25.3鸟哥的备份策略; 25.4灾难恢复的考虑; 25.5重点回顾