How to create RAM disk in FreeBSD

RAM can be used as temporary storage in FreeBSD, offering much faster performance compared to traditional hard drives. However, since RAM is volatile memory, this storage won’t persist through a shutdown or a sudden power loss. In a production environment, you might need a temporary RAM disk to store temporary data without interrupting the actual drives. This is particularly useful in scenarios like FreeBSD-based routing equipment or firewalls.

Create the mount point :

mkdir /diskmnt

Mount ram disk to the mount point , you can specify the size of the disk , I used only 100 MB here .

/sbin/mdmfs -M -S -o async -s 100m md5 /diskmnt

You can vrify by :

df -h

To remove the disk:

umount /diskmnt

You need to release the RAM resource if you are not using it :

mdconfig -d -u 5

You can make the disk permanent by adding the entry in the fstab: