I had the following criteria when configuring the backup for my WordPress installation:

1. Shell Script
2. Protected from the webserver user
3. Works with Dreamhost Enhanced User Security

This approach is based on the script from the WordPress Backup Guide at theme.fm.

In addition to your webserver_user, create a backup_user account. The backup_user will have read access to the website files; however, the webserver_user will not have read access to the backups.

Configure the Accounts

Login as backup_user and run ssh-keygen -t rsa -b <keysize>. Keysize should be 2048 or 4096 (pick the bigger size for more security). Accept all of the defaults. Run cat ~/.ssh/id_rsa.pub and copy the output. Create ~/backup and ~/scripts. Run chmod go-rw ~/backup.

Login as webserver_user and edit/create ~/.ssh/authorized_keys. Add the key copied from id_rsa.pub.

Script Files

Create the following files and make the *.sh files executable:

/home/webserver_user/scripts/opts

[client]
host=<mysql_server>
user=<mysql_username>
password=<mysql_password>

/home/webserver_user/scripts/save.sh

#!/bin/bash

# Make sure we're working in the scripts directory
cd /home/webserver_user/scripts

# Backup the datbase
mysqldump --defaults-file=/home/webserver_user/scripts/opts <wp_datbase> > db.sql

# tar the database backup and all of the WordPress files
# --transform is not necessary, but removes home/webserver_user from the path when extracting
tar czf website-$(date +%Y-%m-%d).tar.gz --transform s,^home/webserver_user/www,www, db.sql /home/webserver_user/www

# Cleanup by removing the uncompressed database backup
rm db.sql

/home/backup_user/scripts/backup.sh

#!/bin/bash

# Set the working directory
cd /home/backup_user/backup

# Run the save.sh script as the webserver_user
ssh webserver_user@webhost.com /home/webserver_user/scripts/save.sh

# Copy the backup to the backup_user account
scp webserver_user@webhost.com:/home/webserver_user/scripts/*.tar.gz ./

# Remove the copy of the backup from the webserver_user
ssh webserver_user@webhost.com 'rm /home/webserver_user/scripts/*.tar.gz'

# cleanup the backup directory and only keep the 3 most recent backups
while [ "$(ls -1t | wc -l)" -gt 3 ]; do
   rm "$(ls -t1r | head -n 1)"
done

Panel Configuration

1. Go to you Dreamhost Web Panel
2. Login
3. Go to Main menu → Goodies → Cron Jobs
4. Click "Add New Cron Job"
   • Select User backup_user
   • Title: backup
   • Email address if you want notification of the script running
   • Command to run: /home/backup_user/scripts/backup.sh
   • When to run: daily or weekly