Simple NAS with a Raspberry PI

For this project, I took a spare Raspberry PI (RPI) and created a low cost NAS with it. I've used a RPI, a 2.5" bus powered hard drive and a USB hub with a 5V/2A power supply. The RPI itself cannot power the hard drive through USB. But, when connected via the hub, it works like a charm.
 

1. Install a SD card with Raspbian
   
   • Download the Raspbian image here: https://www.raspberrypi.org/downloads/
   • Install according to instructions : https://www.raspberrypi.org/documentation/installation/installing-images/README.md
     (you already have the image, continue at "WRITING AN IMAGE TO THE SD CARD" below)
     ​
2. Startup and configuring your RPI
   
   • Put the SD card created in the previous step in your RPI and connect power, wait for the RPI to boot
   • Log on with the pi user (password: raspberry) - note that a notice is displayed that the RPI is not fully configured. You can ignore this message for now. If you have the RPI connected to a display (HDMI), you will see the configuration menu. Do not configure it now.
   • Change to root using: sudo su
   • Update Raspbian using: apt-get update followed by apt-get upgrade (this could take some time). The upgrade will ask you about additional disk space usage, answer Y(es).
   • Now configure the RPI by giving the raspi-config command.
   • A 9 option menu is displayed, we only need to look at the first 4 options.
     
     • Choose option 1: Expand Filesystem and acknowledge the next screen.
     • Choose option 2: Change User Password and change the password for the pi user.
     • Choose option 3: Enable Boot to Desktop/Scratch and select the "Console Text console ..." option.
     • Choose option 4: Internationalisation Options and change Locale, Timezone and Keyboard Layout as required
     • Select Finish to complete the RPI configuration and select Yes to reboot the RPI.
   • After the reboot, log on again with the pi user (password: <you changed it>). Note that you now do not get the notice about configuration, as your RPI has been configured.
      
3. Attaching the USB drive
   
   • ​Verify that you supply your Raspberry with at least a 5V/1A power supply, 5V/2A is better (using a powered USB hub)
   • Use a drive of about 500Gb or more that you can spare for experimenting
   • Attach the (bus powered) drive to your USB hub that you've connected to the RPI.
   • To see what device name it has use this command: dmesg:
      
     [] 1163.294609] usb-storage 1-1.3.4:1.0: USB Mass Storage device detected
     [] 1163.296269] scsi host0: usb-storage 1-1.3.4:1.0
     [] 1164.330052] scsi 0:0:0:0: Direct-Access              Patriot Memory   PMAP PQ: 0 ANSI: 0 CCS
     [] 1164.386652] sd 0:0:0:0: Attached scsi generic sg0 type 0
     [] 1166.867096] sd 0:0:0:0: []sda] 31309824 512-byte logical blocks: (16.0 GB/14.9 GiB)
     [] 1166.867806] sd 0:0:0:0: []sda] Write Protect is off
     [] 1166.867849] sd 0:0:0:0: []sda] Mode Sense: 23 00 00 00
     [] 1166.868448] sd 0:0:0:0: []sda] No Caching mode page found
     [] 1166.868487] sd 0:0:0:0: []sda] Assuming drive cache: write through
     [] 1166.905454]  sda: sda1
     [] 1166.909389] sd 0:0:0:0: []sda] Attached SCSI removable disk
   • Look for the USB Mass Storage message, the example below is showing a 16Gb device that is attached as sda - take note of this device name.
      
4. Configure the USB drive for use​
   
   • Change to root using: sudo su
   • Using the command fdisk - remove existing partitions: fdisk /dev/sda (note: use device name from the step above)
   • To delete existing partitons, use: d
   • When no more partitions exist, create one new partition using: n, p, 1, []default], []default]
   • Then change partition type to Linux using: t, 83 and write changes to disk using: w
   • Now create the filesystem using: mkfs.ext4 /dev/sda1 -c (option -c will check disk for errors before creating file system). If you don’t want to wait a long time then leave out the -c option.
   • Create a mount point in /etc/fstab for the USB drive: vi /etc/fstab and add a line like this:
     /dev/sda1 /home/samba ext4 defaults 0 0
     (I’m mounting under /home but you can also mount under /mnt if you like)
   • Create the directory that you are mounting to: mkdir /home/samba
   • Mount the USB drive manually for testing: mount /dev/sda1 /home/samba
   • After mounting you can show the available space using the df command:
      
     root@raspberrypi:/home# df
     Filesystem     1K-blocks    Used Available Use% Mounted on
     rootfs          15079896 2574784  11842140  18% /
     /dev/root       15079896 2574784  11842140  18% /
     devtmpfs          218636       0    218636   0% /dev
     tmpfs              44584     264     44320   1% /run
     tmpfs               5120       0      5120   0% /run/lock
     tmpfs              89160       0     89160   0% /run/shm
     /dev/mmcblk0p1     57288   19400     37888  34% /boot
     /dev/sda1       15276976   38224  14439676   1% /home/samba
     root@raspberrypi:/home#
      
   • Space is shown in 1K blocks, I have around 14.5 Mb available (I'm using a thumbdrive for testing).
   • Reboot the RPI using the reboot command, logon again and verify that the USB drive is mounted automatically.
      
5. ​    Install and configure Samba
   
   • ​​Change to root using: sudo su
   • Install Samba using: apt-get install samba samba-common-bin samba-tools - the installer will ask you about additional disk space usage, answer Y(es).
   • The installer will start Samba when installation has completed:
     [] ok ] Starting Samba daemons: nmbd smbd.
   • Now all that needs to be done is configuring Samba. I'll show how to create 2 shares, one group share and one public share. The public share is writable for everyone (anonymous) and the group share for all users, like the pi user.
   • Create a backup copy of the samba config file using: cp /etc/samba/smb.conf /etc/samba/smb.conf.org
   • Edit the samba config file using: vi /etc/samba/smb.conf and add 2 share definitions under Share Definitions:
      
     [public]
       comment = Public
       path = /home/samba/public
       valid users = @users
       force group = users
       create mask = 0664
       directory mask = 0771
       writable = yes
     
     [shared]
       comment = Shared
       path = /home/samba/shared
       force user = nobody
       browsable = yes
       public = yes
       writable = yes
          
   • Uncomment this line under Authentication by removing the #:
     security = user
      
   • Under the Global section add:
     guest account = nobody
      
   • Create the 2 directories that will be shared and set access rights:
     #mkdir /home/samba/public /home/samba/shared
     #chown root:users /home/samba/public /home/samba/shared
     #chmod 775 /home/samba/public
     #chmod 777 /home/samba/shared
      
   • Add a Samba password for the users you have, like this:
     #smbpasswd -a pi
      
   • After configuring is done, restart Samba to load the new configuration:
     root@raspberrypi:/home# /etc/init.d/samba restart
     [] ok ] Stopping Samba daemons: nmbd smbd.
     [] ok ] Starting Samba daemons: nmbd smbd.
      
   • Now you can test Samba by connecting (mapping) a network connection to:
     \\raspberrypi\shared or
     \\raspberrypi\public
      
   • You need a username and password (pi + samba password) to connect to public. Create a test folder will show you that the folder was created by the pi user:
      
     root@raspberrypi:/home/samba/public# ls -l
     total 4
     drwxrwxr-x 2 pi users 4096 Aug 16 23:03 Test
     
     If you connect to shared (without username and password) and create a test folder, you will see no owner (nobody):
      
     root@raspberrypi:/home/samba/shared# ls -l
     total 4
     drwxr-xr-x 2 nobody nogroup 4096 Aug 16 23:06 test
      
6. Some notes
   
   • ​The Rasberry PI is not a very fast device when it's about IO and since the drive is USB connected, don't expect commercial NAS performance. But it's a cheap device to play with.
   • I was able to copy about 2.5Mb per second to the Raspberry PI NAS, compared to a similar setup with a BananaPI where I got about 17.5Mb per second
   • Data is stored on a single drive, no RAID or other means of data protection is available.
     
      

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