create raid with two usb disks install tools sudo apt-get install mdadm list block devices sudo blkid create raid sudo mdadm --create --verbose /dev/md/vol1 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1 inspect raid config and persistent it sudo mdadm --detail /dev/md/vol1 sudo mdadm --detail --scan >> /etc/mdadm/mdadm.conf crate file system and mount it sudo mkfs.ext4 -v -m .1 -b 4096 -E stride=32,stripe-width=64 /dev/md/vol1 sudo mkdir /media/raid1 sudo mount /dev/md/vol1 /media/raid1 create fstab link sudo blkid sudo cp /etc/fstab /etc/fstab.bak sudo echo "UUID=UUID-OF-RAID1-DEVICE /media/raid1 ext4 defaults 0 0" >> /etc/fstab