For $1/month, you can learn and practice following root tasks:
* Creating and managing user and group account.
* Resource limits to user and groups.
* Managing sudoer files.
* Apply disk quota to user and groups.
* Disk Formating
* Disk Partitions
* Creating file systems
* Checking filesystem integrity
* Checking disk errors
* Creating swap space
* Using swap space
* System resouces monitoring
* File system usage monitoring
* Monitoring users
* Setting up shell startup scripts.
Above list is just a preview, we will add many more!