NAS | RAID | RPi

Current Features:

RAID 1 configured with mdadm

NAS configured netatalk on AFP

This allows you to drag and drop files to and from your computer and the RPi's Storage over your WiFi

RAID ensures that if one disk fails your data is still 'alive' on the other disk(s)

Mininum Hardware Required:

Raspberry Pi

microSD card, and adapter as needed (microSD -> SD card adapter)

2 USB thumbdrive/flashdrive's (drives/disks from now on)

similar size is best, that way you aren't wasting the larger drives capacity

Your computer, desktop or laptop, for setting up

Router, and Modem to connect to the internet and to connect to RPi

Ethernet cable, to connect RPi directly to router/modem

Minimum Software Downloads:

On your computer:

Balena Etcher

On the RPi:

mdadm

netatalk

Step 1 - Headless Install of RPi

You can skip to 'Step 2' if you already have your RPi up and running

Download Raspberry Pi OS Lite (as it's called now) we don't need a GUI hence Lite https://www.raspberrypi.org/downloads/raspberry-pi-os/

Download Balena Etcher, for flashing the OS to the microSD https://www.balena.io/etcher/

you will have to install the balenaEtcher-*.dmg but that should be straight forward, it's an app like any other

Connect microSD to your computer, via adapter
Open Balena Etcher app and follow the Balena Etcher GUI steps
- select the RPiOS Lite Image, .img file
- select the disk to flash it to and "Flash!" it, be VERY CAREFUL, DO NOT FLASH your HD
- you can look at the Disk Utility app (native to Apple) and make sure it's the microSD you are flashing and NOT your computers HD
  
  notice how the APPLE SD Card Reader Media is only 32.01GB, that is one indicator for me because that is the specific size othe microSD I'm using
Once the flashing is complete, eject the microSD, I use Disk Utility to accomplish this
Reconnect the microSD to your computer and open up your Shell, I use the Terminal app
Create the ssh file by typing the following command into the Terminal

touch /Volumes/boot/ssh

I would make sure your computers file structure is like mine before using this command, i.e. you have root /, Volumes/, and inside Volumes/, you have boot/, so /Volumes/boot/ would be the full path, this shouldn't be a problem if you are using a MacOS

all that is necessary for this part to work is that a blank file with no file extension named ssh is placed in the boot directory of your microSD

Eject the microSD
Connect the microSD to the RPi, connect ethernet from router to RPi, and power on the RPi
From your computer ssh into the RPi

both devices must be connected to the same network, and be on the same subnet

ssh pi@raspberrypi.local

the password is raspberry, so change that as soon as you log in, you can change the password with the command passwd

I would also change the host name of the RPi which can be done in sudo raspi-config or by editing the sudo nano /etc/hosts and sudo nano /etc/hostname files to have a host name of your choosing instead of the name raspberrypi

then restart the RPi to solidify these changes with sudo reboot

Step 2 - Install `mdadm` and configure RAID

Log into your RPi
Update && Upgrade, then download mdadm, if you don't have it already

sudo apt-get update && sudo apt-get upgrade -y && sudo apt-get install mdadm -y

Connect both drives to your RPi

make sure there is NO DATA on the drives, we'll be wiping them

Identify the drives with lsblk

your output should look something like the below

NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda           8:0    1  3.8G  0 disk 
sdb           8:16   1  7.5G  0 disk 
mmcblk0     179:0    0 29.8G  0 disk 
├─mmcblk0p1 179:1    0  256M  0 part /boot
└─mmcblk0p2 179:2    0 29.6G  0 part /

as you may notice the SIZE is 3.8G and 7.5G, this mismatch is fine, it just means we can only store, and mirror data in the size of the smallest disk on the RAID, 3.8G, in other words the largest disk is only utilizing as much space as the smallest disk

Wipe each disk with zeros

this will take some time depending on the size, so for experimentation use small drives

you can wipe both simultaneously, just open up another shell (Terminal) and wipe the other disk in there, so they'll be running concurrently in different windows

sudo dd if=/dev/zero of=/dev/sdX bs=1M status=progress

where the X in sdX is either a in sda, or b in sdb, etc for all drives you use in this experiment

there are best practices for bs=someValue but for this tutorial we'll keep it simple

output will look something like this

212860928 bytes (213 MB, 203 MiB) copied, 5 s, 42.3 MB/s

until it's complete, then it'll look like below

dd: error writing '/dev/sda': No space left on device
7651+0 records in
7650+0 records out
8021606400 bytes (8.0 GB, 7.5 GiB) copied, 860.048 s, 9.3 MB/s

error writing '/dev/sda': No space left on device means that there were no more spaces to write in 0's, so it's all finished don't be concerneds

Create RAID 1

if you are adding more than 2 devices then change --raid-devices=n accordingly, where n is the number of devices

sudo mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sdX /dev/sdY

you should get a similar output as below

mdadm: Note: this array has metadata at the start and
    may not be suitable as a boot device.  If you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
mdadm: size set to 3912704K
mdadm: largest drive (/dev/sdb) exceeds size (3912704K) by more than 1%
Continue creating array?

type yes and press enter, you should see something like what's below

mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

Monitor the syncing

watch cat /proc/mdstat

to view the progress

to get out of it this view hold ctrl and press C

the output should be similar to what is below

Personalities : [raid1] 
md0 : active raid1 sdb[1] sda[0]
      3912704 blocks super 1.2 [2/2] [UU]
      [====>................]  resync = 20.8% (815424/3912704) finish=5.3min speed=9557K/sec
      
unused devices: <none>

and like the below when complete

Personalities : [raid1] 
md0 : active raid1 sdb[1] sda[0]
      3912704 blocks super 1.2 [2/2] [UU]
      
unused devices: <none>

Create ext4 filesystem on RAID 1 sudo mkfs.ext4 -F /dev/md0

you'll get a similar output to the below, just give it a moment, depending on disk size

mke2fs 1.44.5 (15-Dec-2018)
Creating filesystem with 978176 4k blocks and 244800 inodes
Filesystem UUID: f3e988bf-2f9a-4637-9ae6-f4e451b18526
Superblock backups stored on blocks: 
    32768, 98304, 163840, 229376, 294912, 819200, 884736

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done

Create mount point for the RAID

sudo mkdir -p /mnt/md0

Mount the RAID

sudo mount /dev/md0 /mnt/md0

Check that drive is mounted and how much space it has sudo mdadm -D /dev/md0

output should look similar to below

Array Size : 3912704 (3.73 GiB 4.01 GB)

/dev/md0:
           Version : 1.2
     Creation Time : Tue Sep  1 01:10:40 2020
        Raid Level : raid1
        Array Size : 3912704 (3.73 GiB 4.01 GB)
     Used Dev Size : 3912704 (3.73 GiB 4.01 GB)
      Raid Devices : 2
     Total Devices : 2
       Persistence : Superblock is persistent

       Update Time : Tue Sep  1 01:26:42 2020
             State : clean 
    Active Devices : 2
   Working Devices : 2
    Failed Devices : 0
     Spare Devices : 0

Consistency Policy : resync

              Name : cloudstore:0  (local to host cloudstore)
              UUID : ee7f51b7:d27ab855:b9c5e4a0:88ad4ef1
            Events : 17

    Number   Major   Minor   RaidDevice State
       0       8        0        0      active sync   /dev/sda
       1       8       16        1      active sync   /dev/sdb

Used Dev Size : 3912704 (3.73 GiB 4.01 GB)

from what I've read this means unused space, which makes sense since it's all fresh, I wouldn't read into it too much

Step 3 - Install `netatalk` and configure NAS

Install netatalk, you should be logged into the RPi for these steps as well

sudo apt-get install netatalk -y

Configure netatalk

sudo nano /etc/netatalk/afp.conf

defines home directory, allows users to access ‘home’ folder, I named mine My RAID with a directory name of my_raid

/media/my_raid/shared is the full path to the accessible portion of the RAID

unless you are using a different distribution than I am RPi OS Lite then you shouldn't have to worry about the path being incorrect, you can name the my_raid portion whatever you like

edit the configuration file to reflect the below entry, either by the modifiying [My AFP Volume] entry or by adding your own, uncommented entry

if it is 'commented out' then the configuration won't be read by the program

[My RAID]
path = /media/my_raid/shared
; are comments, again semi-colons are comments

Make directory RAID

sudo mkdir /media/my_raid

List out RAID with disks UUID's

lsblk --fs | grep md0

copy UUID

mine looks like

f3e988bf-2f9a-4637-9ae6-f4e451b18526

will be similar to the below

└─md0       ext4                           f3e988bf-2f9a-4637-9ae6-f4e451b18526    3.4G     0% /mnt/md0
└─md0       ext4                           f3e988bf-2f9a-4637-9ae6-f4e451b18526    3.4G     0% /mnt/md0

Add copied UUID as entry to fstab

sudo nano /etc/fstab

add UUID=f3e988bf-2f9a-4637-9ae6-f4e451b18526 /media/my_raid ext4 defaults 0 2 to the bottom of fstab, make sure the UUID is equal to what you copied in step 4

/etc/fstab file will look like the following

proc            /proc           proc    defaults          0       0
PARTUUID=853f83f4-01  /boot           vfat    defaults          0       2
PARTUUID=853f83f4-02  /               ext4    defaults,noatime  0       1
# a swapfile is not a swap partition, no line here
#   use  dphys-swapfile swap[on|off]  for that

Restart netatalk

sudo systemctl restart netatalk

Mount RAID

sudo mount -a

Make shared directory and change permissions

sudo mkdir /media/my_raid/shared

sudo chmod 777 /media/my_raid/shared

cat /proc/mdstat is a great way to ensure the RAID is functioning but you can also inspect with the lsblk --fs | grep md0 command

if all disks are mirroring properly you should see the % change for all disks when you modify the data, i.e. add or remove files from the RAID e.g.

└─md0       ext4                           f3e988bf-2f9a-4637-9ae6-f4e451b18526    3.4G     0% /media/my_raid
└─md0       ext4                           f3e988bf-2f9a-4637-9ae6-f4e451b18526    3.4G     0% /media/my_raid

└─md0       ext4                           f3e988bf-2f9a-4637-9ae6-f4e451b18526    2.1G    36% /media/my_raid
└─md0       ext4                           f3e988bf-2f9a-4637-9ae6-f4e451b18526    2.1G    36% /media/my_raid

Step 4 - Connect to RAID Storage from Computer

Open a Finder window, method differs for MacOS 10.13 and 10.14 or higher

In the Finder's sidebar
- For 10.13 and below, under Shared look for the RPi's hostname
- For 10.14 and above, under Locations look for the RPi's hostname or Network
  - if you don't see the hostname under Locations then select Network, under Locations and select the hostname

Select and open hostname

You'll be put into a Finder window that states it is 'Not Connected'

Select Connect As and fill out credentials

Now you should be logged in, you can open My Raid and start storing data in it You can drag from your desktop to the RAID storage, and from the RAID storage to your desktop

All Done!

I'll be adding more to this README.md
- how to remove and add disks
- VPN setup to access from anywhere like a 'cloud'
- using Windows to setup/administer
- troubleshooting
As I learn more I will create a more in depth ReadMe