原来一直用tar、sync等软件实现备份。需要些脚本还要找一台其他服务器进行同步。现在有了DROPBOX这个网站提供的服务，一切都变容易了。

DROPBOX网站： http://www.dropbox.com/ DROP功能： 偷懒直接把官方介绍帖过来了。主要就是免费提供2G的同步空间，可以自动同步文件并保留文件的历史版本

Dropbox Features

File Sync

Dropbox allows you to sync your files online and across your computers automatically.
  • 2GB of online storage for free, with up to 100GB available to paying customers.
  • Sync files of any size or type.
  • Sync Windows, Mac and Linux computers.
  • Automatically syncs when new files or changes are detected.
  • Work on files in your Dropbox even if you’re offline. Your changes sync once your computer has an Internet connection again.
  • Dropbox transfers will correctly resume where they left off if the connection drops.
  • Efficient sync - only the pieces of a file that changed (not the whole file) are synced. This saves you time.
  • Doesn’t hog your Internet connection. You can manually set bandwidth limits.

File Sharing

Sharing files is simple and can be done with only a few clicks.
  • Shared folders allow several people to collaborate on a set of files.
  • You can see other people’s changes instantly.
  • A “Public” folder that lets you link directly to files in your Dropbox.
  • Control who is able to access shared folders (including ability to kick people out and remove the shared files from their computers).
  • Automatically create shareable online photo galleries from folders of photos in your Dropbox.

Online Backup

Dropbox backs up your files online without you having to think about it.
  • Automatic backup of your files.
  • Undelete files and folders.
  • Restore previous versions of your files.
  • 30 days of undo history, with unlimited undo available as a paid option.

Web Access

A copy of your files are stored on Dropbox’s secure servers. This lets you access them from any computer or mobile device.
  • Manipulate files as you would on your desktop - add, edit, delete, rename etc.
  • Search your entire Dropbox for files.
  • A “Recent Events” feed that shows you a summary of activity in your Dropbox.
  • Create shared folders and invite people to them.
  • Recover previous versions of any file or undelete deleted files.
  • View photo galleries created automatically from photos in your Dropbox.

Security & Privacy

Dropbox takes the security and privacy of your files very seriously.
  • Shared folders are viewable only by people you invite.
  • All transmission of file data and metadata occurs over an encrypted channel (SSL).
  • All files stored on Dropbox servers are encrypted (AES-256) and are inaccessible without your account password.
  • Dropbox website and client software have been hardened against attacks from hackers.
  • Dropbox employees are not able to view any user’s files.
  • Online access to your files requires your username and password.
  • Public files are only viewable by people who have a link to the file(s). Public folders are not browsable or searchable.

Mobile Device Access

The free Dropbox iPhone app lets you:
  • Access your Dropbox on the go.
  • View your files on your iPhone or iPod Touch.
  • Download files for offline viewing.
  • Take photos and videos and sync them to your Dropbox.
  • Share links to files in your Dropbox.
  • View interactive photo galleries.
  • Sync downloaded files so they’re up-to-date.
 

A mobile-optimized version of the website is available for owners of Blackberry phones and other Internet-capable mobile devices.   Linux下安装

如果你的Linux服务器安装了Xserver和桌面，完全可以安装官方的指南来安装。但是因为一般的VPS都内存小得可怜，不会奢侈到安装桌面，所以下面主要介绍在没有安装桌面系统的命令行Linux下安装步骤。 关于安装方法的内容转帖自http://lazyhack.net/install-dropbox-in-vps/ 1、登陆进VPS或者是服务器，进入用户目录

  1. cd
2、下载dropbox的客户端，要For linux那个而非For Nautilus的 这里我是在http://lazyhack.net/install-dropbox-in-vps/文档中找到的地址，官方网站找了半天都是Nautilus的版本 32位下载地址 http://www.dropbox.com/download?plat=lnx.x86 64位下载地址 http://www.dropbox.com/download?plat=lnx.x86_64 我这里用的32位系统，所以下载32位客户端
3、解压
  1. tar zxvf dropbox-lnx.x86-0.7.110.tar.gz
4、下载dbmakefilelib.py并运行
如果出现以下信息，说明它运行正常 dropboxd ran for 15 seconds without quitting - success? 看到它的提示了吗，Dropbox已经启动了，让你运行15秒后再退出，这个过程就是dropbox生成机器信息并保存到db文件的，其实对于国外的vps来说几秒时间就够了，我们ctrl－c将其退出，完成接下来的步骤
  5、进入Dropbox的dot目录导出机器信息
  1. cd .~/.dropbox
  2. $ sqlite3 dropbox.db
  3.  
  4. SQLite version 3.6.22
  5. Enter “.help” for instructions
  6. Enter SQL statements terminated with a “;”
  7. sqlite> .dump config
我们会在导出的信息中看到如下的一串字符 
INSERT INTO “config” VALUES(4,‘host_id’,‘VmQ0NWFlMTdmYmQ3OGYzMzgyOTM0NWMzN2Q1MGFkOTIzCnAxCi4=
‘);
这个host_id就是机器的唯一标识，我们需要用它来跟自己的账户进行匹配，不过在这之前还有个工作需要做，因为上面的那长串字符很明显可以看出 是用base64编码后的结果，我们得先把它解码再说，注意这里Dropbox耍了个小花招，这串字符串前面的那个”V“，是无用的，我们在解码后的把它 忽略掉
  6、将base64字符串解码  

$ echo mQ0NWFlMTdmYmQ3OGYzMzgyOTM0NWMzN2Q1MGFkOTIzCnAxCi4= ｜ base64 -d
  1. Vd45ae17fbd78f33829345c37d50ad923
  2. p1 
我的结果是Vd45ae17fbd78f33829345c37d50ad923，忽略掉”V“，就是d45ae17fbd78f33829345c37d50ad923
         7、将账户信息与机器信息绑定
这步很简单，只需要访问以下网址，并登陆
HOSTID替换成你刚才解码出来的那串字符就行了 
https://www.dropbox.com/cli_link?host_id=HOSTID
8、建立dropbox的同步目录
dropbox的同步目录默认的是~/Dropbox 
$ mkdir ~/Dropbox
9、运行，开始你的同步 $ ~/.dropbox-dist/dropboxd & 到这里dropbox就可以正常运行并同步了，文章标题说的是备份网站数据，那么我们就来使我们的网站数据能够同步到dropbox服务器上
其实很简单，就是建立符号连接而已，windows之前是没有这个功能的
比如要备份/var/www这个目录 
cd ~/Dropbox
$ ln -s /var/www web_backup
这就可以了,或者要备份/etc目录 
$ cd ~/Dropbox
$ ln -s /etc etc_backup
ok.发挥你的想象尽情的使用吧。
  推广 如果你看过这篇文章后，打算也使用dropbox。那么你可以使用我下面的链接注册 https://www.dropbox.com/referrals/NTU4NDMyNzI5 采用这个链接注册，你会增加250M空间。注册后是2G，然后会给你再发封邮件告诉你已经提升到2.25G。而我也会增加250M空间。