Firstly we need to add the second disk, if your Pfsense firewall is virtualised it is best to do this while the machine is powered off. Attach the second disk at the required size then power up your machine.
Once the Firewall has booted you will need to log in via SSH and press 8 to connect to the server’s shell. See here on how to enable SSH on your Pfsense Firewall.
Now, make a ‘Mount point’ for the new disk to reside on your filesystem.
We will now need to find out what unique name your disk has been given. You can do that by listing all disk devices on your Firewall by running the following command.
gpart list -a
This will show you all disks and partitions attached to your machine (Examples below).
Geom name: ad0 modified: false state: OK fwheads: 15 fwsectors: 63 last: 31457279 first: 63 entries: 4 scheme: MBR Providers: 1. Name: ad0s1
In the example above, ad0 is the name of the physical disk and ad0s1 is the name of the partition on the disk. We will now need to create a parition scheme and partition on our new drive (This will be ad1 in a typical setup).
gpart create -s GPT ad1 gpart add -t freebsd-ufs ad1
We will now need to make a filesystem in the new partition:
newfs -U /dev/ada1p1
Now, exactly the same as our guide for Ubuntu we will need to modify fstab to ensure that this partition is mounted each time the server boots.
And add the following line (The headers at the top of the file should explain what each column is used for).
/dev/ad1p1 /media/squid ufs rw 2 2
You can now mount the disk manually without having to reboot by running the below – Alternatively reboot your system to confirm your fstab line works as required.
Confirm the disk is mounted by running the mount command and ensuring you can see your new parition mounted in the required location
mount /dev/ad1p1 on /media/squid (ufs, local, soft-updates)