I’m thinking about how to backup personal data, we can divide them into groups which according to their importance, file size, and privacy.

• Important, Big size, Sensitive: Computer full disk data.
• Important, Small size, Sensitive: key information, like daily.
• Unimportant, Middle size, Sensitive: photos.
• Unimportant, Big size, insensitive: film, comics.

We can use different methods to backup them, vary in price, space, security, and usability:

• Encrypted online backup service: high price, small space, secure, hard to use.
• Online backup service: fair price, small space, insecure, easy to use.
• NAS/Portable disk drive: low price, big space, secure, hard to use.

So, this is the method I’m using now:

• Use timemachine to backup computer into portable disk drive.
• Use lastpass to keep website and server password.
• Use dropbox to save and sync notes, photos, and documents, I extended it to 20G.
• Use portable disk drive to backup film, music and comics.