利用 cron 與 rsync 備份資料

Reference：
鳥哥的私房菜 - 例行性工作排程、rsync manual、A turial on using rsync、rsync example、tar - exclude files

上次電腦當機後，決心要幫電腦資料做定期備份，才不會一次打破整籃雞蛋，我的構想是每天晚上利用 rsync 備份更動最頻繁的 home 到另一顆硬碟上，每周五利用 tar 將不見時會搥心肝的重要資料打包成 gz 存到另一顆硬碟，再燒到光碟上，並存入隨身碟，總共存放在三處，如此一來，資料消失在世界上的風險性相信可以大大降低。

不過存放備份的硬碟是 fat 格式，造成 rsync 時沒辦法複製權限和一堆有的沒的東東而錯誤，卡在那邊花了不少時間，後來就隨它去了，不能設權限也沒差，反正資料在就好，而且用 tar 打包時就可以保留檔案權限了，而 tar 時原本想用 bzip2 或 lzma 壓縮，但是所花的時間多到讓我受不了，乾脆用簡單的 gzip ，有壓總比沒壓好，下一步要把 anacron 搞懂，才不會因為有時電腦沒開而少了一次備份。

備份的 script 都是用 python 寫的，rsync 的 exclude 跟 tar 有點不太一樣，為了研究這個還花了不少時間， 不過有了範本後，下次要寫其他 script 應該可以更快上手。
rsync script：

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# use 'rsync' to backup files to a fat partition
# write logs into log_file

import time
import sys
import subprocess as sp

# not configure ACL, xattrs currently(can use -AX to sync)
# the same as -va --compress -stats --delete
# args = " --verbose --archive --compress --stats --delete "

# because sync file from ext3 to vfat lead to errors (vfat don't have
# some file attributes), need to remove some args
args = " --verbose --recursive --times --compress --delete "

# need to sync some windows program, so use exclude
# instead of --cvs-exclude
ex_PATTERN = [ "*~", "*.pyc",\
             "**cache**","**Cache**","**CACHE**", "**.macromedia/",\
             "**.opera/icons/", "**.thumbnails/"]

exclude = ''.join( map( lambda p: " --exclude=" + p, ex_PATTERN))

SRC = " /home/myHome"
DEST = " /mnt/HardDisk/back/sync"
# there is also --log-file=FILE option
log_file = "/home/mylog.log"

def write_log( messages ):
  with open(log_file, 'a') as f:
      f.writelines("\n***************************************\n")
      f.writelines( time.ctime() )
      f.writelines("\n***************************************\n")
      f.writelines( messages )

try:
  ret = sp.Popen(["rsync" + args + exclude + SRC + DEST],\
      stdout=sp.PIPE,shell=True).communicate()[0] 
  write_log(ret)
except OSError, e:
  write_log("Execution failed:" + e )

tar script：

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# use 'tar' to backup files, save them as my_tar_Year_Month_Day.tar.gz
# write logs into log_file

import time
import sys
import subprocess as sp

# use -f in front of DEST to prevent args mix up
args = " -czv --exclude-caches-all"

SRC = " /mnt/HardDisk/my_precious \
      /mnt/HardDisk/rotl "

TIME_STRING =  time.strftime( "%Y_%m_%d", time.localtime() )

DEST = " /mnt/HardDisk/bak/mytar_" + TIME_STRING + ".tar.gz"

log_file = "/home/mytargz.log"

ex_PATTERN = [ "*~", "*.pyc",\
             "**cache**", "**Cache**","**CACHE**",\
             "**.macromedia/", "**.opera/icons/", "**.thumbnails/"]

exclude = ''.join( map( lambda p: " --exclude=" + p, ex_PATTERN))


def write_log( messages ):
  with open(log_file, 'a') as f:
      f.writelines("\n***************************************\n")
      f.writelines( time.ctime() )
      f.writelines("\n***************************************\n")
      f.writelines( messages )

try:
  # use -f in front of DEST to prevent args mix up
  ret = sp.Popen(["tar" + args + exclude + " -f " + DEST + SRC ],\
      stdout=sp.PIPE,shell=True).communicate()[0]
  write_log(ret)
except OSError, e:
  write_log("Execution failed:" + e )