By creating a public/private SSH keypair, and uploading the public key to your rsync.net filesystem, you can allow your backup process to authenticate without your password.

Generating the SSH Keypair

First, log into your unix system as the user that your backups will run under. So, if your backups will run as the root user (which is very common) you need to log in as root.

Now run the following command:

ssh-keygen -t rsa -b 4096

Accept the defaults - do not change the filenames or file locations It is very important that the resultant private and public keys reside in your home directories .ssh directory, or ~/.ssh (which is the default)

DO NOT enter a passphrase - just hit enter twice, leaving an empty passphrase.

Uploading Your Public Key

Upload your newly created public key using this command:

scp ~/.ssh/id_rsa.pub 123@tv-s009.rsync.net:.ssh/authorized_keys

DO NOT change the permissions on the uploaded file, before or after the upload

DO NOT change the permissions on your home directory, or your .ssh directory

NOTE: 123@tv-s009 is most certainly NOT your login ID or hostname - please change them.

Testing Your Passwordless Login

Test that your key works by ssh'ing to your rsync.net filesystem (from your local system, as the user who created/uploaded the key):

ssh 123@tv-s009.rsync.net ls

You should not be asked for a password

Multiple Keys (optional)

It is possible to upload multiple public keys to your rsync.net account, allowing one or more users on one or more computer systems to log in without a password. However, you cannot just follow the above instructions over and over again, because each time you follow them, you will overwrite the previous key.

Instead, do this:

1. For the first user on the first computer system, follow the instructions above exactly.

2. For each subsequent user (possibly on different computer systems), replace the 'scp' step in the above instructions with:

   cat ~/.ssh/id_rsa.pub | ssh 123@tv-s009.rsync.net 'dd of=.ssh/authorized_keys oflag=append conv=notrunc'

3. Repeat this process for each user until you have a fully populated authorized_keys file in your rsync.net account.