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MDADM RAID 0 (Striping)

Install Dependencies​

Install mdadm if it is not already installed

sudo apt update && sudo apt install mdadm

Identify Disks​

warning

Make absolutely sure you are selecting the right disk as proceeding with the incorrect disk will result in data loss

List the block devices available on your systems

lsblk

From the output I have identified sda and sdb as the disks I want to use for my RAID 0 setup.

Prep Disks​

warning

Be certain to perform these actions only on the disks you plan to use for the array

Existing partitions should be removed. This can be done with fdisk

sudo fdisk /dev/<DEVICE>

Press d to delete the partition, then ENTER to select the first applicable parition. Repeat until all partitions are removed. Type w to write the changes and exit.

Create the Array​

Execute the mdadm command to create the array

sudo mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/sda /dev/sdb

This command tells mdadm to create the array the /dev/md0 location using RAID level 0, with 2 RAID devices which consist of /dev/sda and /dev/sdb. You will want to make sure that you update the number of raid-devices and the actual device locations to represent your system's configuration.

Format the Array​

I will be using ext4 as the file system for my array

sudo mkfs.ext4 -m 0 /dev/md0

This simple command formats the /dev/md0 array we created in the previous command. The -m 0 will set the reserve space to 0 which is fine for a non-root partition.

Mount the Drive​

Create a mount point for the drive. I will mount to /media/raid0 but you can mount where it makes the most sense for you.

mkdir /media/raid0

Then mount the drive

sudo mount /dev/md0 /media/raid0

Check the Status​

To see the status of your RAID array, run

cat /proc/mdstat

Automatically Mount on Boot​

If you want the drive to automatically be mounted when you boot, you need to create an FSTAB entry. First, identify the UUID of your raid array

sudo blkid /dev/md0

Copy the UUID listed. Then open up your FSTAB file

sudo nano /etc/fstab

Then add the following entry at the bottom of your FSTAB file

UUID=<UUID> /media/raid0 ext4 defaults,nofail 0 0

This mounts the drive with the specified UUID to the /media/raid0 mount point with the ext4 file system using the default mount options + nofail which allows the system to still boot if the device is not available. 0 0 means do not dump the file system and do not perform a file system check, which is fine for a non-root filesystem.

To save and exit, press CTRL + x then y.

Speed Test (Optional)​

If you want to test out the performance of you new RAID array, you can perform some benchmarks with fio. Check out the wiki for testing drive performance for instructions on how to do it.