Laptop Backup via Rsync + iPod

My previous post talked about using rsync to backup securely to another computer over the Internet. What if you want a local spare backup or do not have Internet?

Here is what I did on my mac powerbook.

Set your iPod so you can use it as a removable drive. iPod has to be set to “Enable Disc Use”.

Create an Encrypted Sparse Disc Image on the iPod. You can just follow the directions over on

hdiutil create -size 5g -encryption -type SPARSE -fs HFS+ Backup

That creates an encrypted sparse image file named Backup that maxes out at 5GB. We open the image once, and rename the Drive name label to EncryptBackup. That will be what shows if we look at the mounted volumes.

Now all you have to do is use a nice rsync command to backup your documents into the mounted encrypted Spare Image.

rsync -avg –exclude “Documents/browseback/” ~/Documents /Volumes/EncryptBackup

That will sync our Documents folder over into the Encrypted Backup image file on the iPod just as if it were its own drive. Note the –exclude option. I have a program called BrowseBack for the Mac. It caches copies of everything I browse there so I can find previous content again via web, send to pdf, email etc. But I don’t want to backup all that cached data.


Modified the script I have on my iPod to mount, backup then dismount the image.

hdiutil attach /Volumes/iPod/Backup/Backup.sparseimage
rsync -avg –exclude “Documents/browseback/” ~/Documents /Volumes/EncryptBackup
hdiutil detach /Volumes/EncryptBackup

Then an Automator saved as an application onto the iPod and its an easy double click. If you save your image’s password in your keychain you won’t have to enter that either.


Laptop Backup via Rsync + SSH

I was playing around with rsync the other night. Now I have a scripted command so I can backup folders from my laptop back to the external harddrive on my iMac at home. You can find the command below.

We need to assume you have done several a couple of things to improve the security of your SSH at home.

  1. Moved from the standard tcp 22 port to a new port: example 5346
  2. Turned off password authentication in favor of public-private key authentication.
  3. Have your ssh private key saved somewhere on your laptop simple like the default ~/.ssh folder. The default keyname is id_rsa if you generated your key with a command like
    ssh-keygen -t rsa
  4. The folder we want to backup is called Documents just in our home folder on our Apple Powerbook.
  5. We will assume you registered a Dyndns name for you home machine.: example
  6. The username on your home iMac or *nix box is: username
  7. The external drive is called: ExternalDrive

Here is the command you would issue on your Mac or *nix laptop. It should all be on one line. The best part is that it will take a while depending on how much stuff you have in your Documents folder. After that it will only sync over the changes. Perfect when away from home and you want a backup safely off your laptop.

rsync -avrz -e “ssh -p 5346 -i .ssh/id_rsa” Documents