On FreeNAS, when setting up the hard drives to store your files, you have to create a pool, which is a logical group of physical drives that you can then use to create volumes (vdevs) using ZFS. However, before you create a storage pool, you need to decide the level of redundancy. FreeNAS uses ZFS, which is a robust file system that offers many levels of redundancy, including RAIDZ1, RAIDZ2, RAIDZ3, Stripe, and Mirror.
Although you can use any of the redundancy levels, RAIDZ2 is perhaps your best option when setting up a home or office network storage system. The RAIDZ2 requires at least four drives, and despite the usable storage will be reduced by the number of two drives, you can have up to two drive failures without losing your files.
In comparison, Stripe requires at least one drive, and it’s more suited for performance, but if you lose one of the drives, you’ll lose all your data. Mirror requires at least two drives, and whatever you copy on one of the drives, it’ll automatically replicate to the second drive, which losing either of the drives won’t cause data loss.
The RAIDZ1 requires at least three drives, but if you lose a second drive during rebuild or while you’re ordering a replacement, you’ll lose all your data. Finally, RAIDZ3 requires at least five disks, and it’s similar to RAIDZ2, with the exception that up to three disks can fail before you lose your data.
In this guide, you’ll learn the steps to create a RAIDZ2 storage pool to provide good redundancy and performance balance your FreeNAS server (version 11.2 and higher).
How to create RAIDZ2 storage pool using FreeNAS
To create a RAIDZ2 pool on FreeNAS, use these steps:
Sign into root account.
Click on Storage from the left pane.
Click on Pools.
Under the “Pools” section, click the Add button.
Select the Create new pool option.
Click the Create Pool button.
Type a name for the new storage pool — for example, StorageCollection1.
(Optional) Check the Encryption option.Quick note: Encryption is not required, but it’s recommended, so you don’t have to worry about your data when you need to send faulty drive to repair or recovery.
Check the Confirm option.
Click the I Understand button.
Under the “Available Disks” section, select the drives that will participate in the storage pool. (You’ll need at least four drives to create a RAIDZ2 configuration.)
Click the Right arrow button to add the drives to the “Data VDevs” section.
Under the “Data VDevs” column, use the drop-down menu and select the Raid-z2 option to create a storage pool .Quick note: When using a RAID-z2 configuration, the parity doubles similar to a RAID6 setup, which means that the disk array can lose up to two drives without losing your data.
Click the Create button.
Click the Confirm option.
Click the Create Pool button.
Click the Download Recovery Key button if you selected the “Encryption” option, and then the Done button once you saved the file key.
Once you complete the steps, the FreeNAS RAIDZ2 pool will be created, and you can now proceed to create a dataset that will host folders that you want to share in the network.