Documentation by Dysphunkional
To be able to use FreeNAS as a file server we have to configure the storage that is hooked up to it first. If your system can handle it go with ZFS for your storage it makes it much easier to manage than UFS.
Creating a ZFS Volume
To create a ZFS pool go to Storage -> Volumes -> ZFS Volume Manager.
Give your volume a name in the Volume Name box.
If you click the + button in the Available Disks box FreeNAS will choose the optimal configuration for your drives.
You can change the type of volume and the number of disks in the Volume Layout box. The different types are described in the FreeNAS Raid Overview.
Click the Add Volume button to create the volume.
Create a Dataset
ZFS datasets are similar to partitions on regularly managed hard disks in that they split a drive, or ZFS pool in this case, into separate areas that can have different properties, permissions, quotas, etc. It also makes it easy for FreeNAS to share out portions of the overall file system. The only real downside to using datasets is that like with partitions when you move a file from one dataset to another it actually does a copy and delete instead of just changing the index to the file. Datasets can have subdatasets as well so you can create a hierarchy of datasets to organize your storage.
To create a dataset go to Storage -> Volumes -> View Volumes.
Type a name for the dataset into the Dataset Name box and then click the Add Dataset button.
You can repeat these steps to create as many datasets as you need. I like to create 2 main datasets one called “jails” for Jails and a second dataset called “shares” for all the stuff I plan on sharing. FreeNAS will automatically make subdatasets for any jails you create. I like to make subdatasets in my shares dataset for my private data (data), publicly available data (public) and one for each type of media (pictures, music, and video.) Once you are done creating datasets it should look something like this: