Category Archives: Raspberry Pi

Mounting a USB HDD on Ubuntu server

I’m running up my latest Raspberry Pi with a connected USB SSD and forgot how to mount the thing. So this post is a little reminder. Ofcourse the instruction are not exclusive to Raspberry Pi’s or Ubuntu, but hey I just wanted a back story to this post.

So you’ve connected your USB drive and you’ve got a SSH terminal (i.e. via PuTTY) session connected to you Ubuntu server, what’s next?

Where’s my drive

The first thing you need to figure out is where your drive is, i.e. what /dev/ location it’s assigned to.

  • Try running df, which reports disk space and usage, from this you might be able to spot your drive, in my case it’s /dev/sda1 and its obvious by the size of the drive
  • If this is not conclusive then run sudo fdisk -l this may help locate the disk

Mounting the drive

Assuming we’ve located the device, and for this example it is on /dev/sda1, how do we mount this drive?

  • Create a folder that will get mapped to our mounted drive, for example mkdir /media/external or whatever you want to name it
  • To mount the drive we now use 
    sudo mount -t ntfs-3g /dev/sda1 /media/external

    Obviously this drive I’m mounting is an NTFS formatted drive, you might be using vfat or something else instead, so check. Then we simply have the source (/dev/sda1) mapping to the destination (/media/external) that we created.

    Note: without the mount taking place, ls the destination and you’ll see no files (if they exist on your drive). After you mount the drive. ls the destination to see the files on the USB drive.

As it currently stands, when you reboot you’ll have to mount the drive again.

Auto-mounting the drive

In scenarios where we’re not removing the drive and simply want the OS to automount our drive, we need to do a couple of things.

  • Find the UUID for the drive by running sudo blkid, next to the device, i.e. /dev/sda1 should be a UUID, copy or note down the string.
  • Run sudo nano fstab
  • Add a new line to the bottom of the file along these lines 
    UUID=ABCDEFGHIJK /media/external auto nosiud,nodev,nofail 0 0

    and save the file

  • Run sudo mount -a to check for errors

Now when you reboot the machine the USB drive should be mounted automatically.

Turning my Raspberry Pi Zero W into a Tomcat server

I just got hold of a Raspberry Pi Zero W and decided it’d be cool/fun to set it up as a Tomcat server.

Docker

I am (as some other posts might show) a bit of a fan of using Docker (although still a novice), so I went the same route with the Pi.

As per the post Docker comes to Raspberry Pi, run the following from you Pi’s shell

curl -sSL https://get.docker.com | sh

Next, add your username to the docker group (I’m using the standard pi user)

sudo usermod -aG docker pi

Pull Tomcat for Docker

Don’t forget, the Raspberry Pi uses an ARM processor, so whilst Docker can help in deploying many things, the image still needs to have been built on the ARM processor. Hence just trying to pull Tomcat will fail with a message such as

exec user process caused “exec format error”

So to install Tomcat use the izone image

docker pull izone/arm:tomcat

Let’s run Tomcat

To run Tomcat (as per the izone docker page). Run

docker run --rm --name Tomcat -h tomcat \
-e PASS="admin" \
-p 8080:8080 \
-ti izone/arm:tomcat

You’ll may need to wait a while before the Tomcat server is up and running, but once it is simply use your browser to navigate to 

http://<pi-zero-ip-address>:8080/

and you should see the Tomcat home page.

Setting up my Raspberry Pi

As this is the third Raspberry Pi I’ve had to set up, and again I’ve forgotten the steps. Here’s a post of what I need.

Steps…

  1. Ensure the OS is upto date
  2. Setup a WiFi USB device (I’m using the EDIMAX USB Adapter)
  3. Setup a static IP address
  4. Install mono
  5. Install Git tools
  6. Setup VNC

Fire up the Pi and login…

Ensure the OS is upto date

sudo apt-get update

This will update all packages.

You can also run

sudo apt-get upgrade

to upgrade the Linux kernel

Setup a WiFi USB device (I’m using the EDIMAX USB Adapter)

The EDIMAX EW-7811Un is on the list of WiFi USB adapters that’s verified for use on a Raspberry Pi and it’s the one I’ve used previously so I know it works :)

Note: An excellent and fuller guide is available at Raspberry Pi – Installing the Edimax EW-7811Un USB WiFi Adapter (WiFiPi)

I’ll just reproduce the steps I used here

  1. So obviously we need to start by plugging the USB adapter into the Raspberry Pi
  2. Next run 
    iwconfig

    This will tell us whether the adapter is ready to use as it should automatically have been recognized. You should see wlan0 plus other information output. Check the link above for more tests you can do to ensure everything is detected and read.

  3. Now we want to ensure that the adapter is configured, so type 
    sudo nano /etc/network/interfaces

    or use your preferred text editor in place of nano.

    Make sure the file contains the following (and they’re uncommented)

    allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp
  4. Now we need to create/amend the configuration file for connecting to the network, so type 
    sudo nano /etc/wpa_supplicant/wpa_supplicant.conf

    We need to add the various entries for connecting to the network here, for example

    network={
   ssid="The Router SSID"
   psk="The Router Password"
   proto=WPA
   key_mgmt=WPA-PSK
   pairwise=TKIP
   auth-alg=OPEN
}

    Obviously replace the ssid and psk with your router’s ssid and the password you use to connect to it.

  5. Type the following, to restart the network interface with the new configuration data

    sudo ifup wlan0

Setup a static IP address

Open /etc/network/interfaces again, for example using

sudo nano /etc/network/interfaces

We now want to change the configuration from using dhcp supplied address to using a static ip address. So alter the line

iface default inet dhcp

from dhcp to static and add the following

address 192.168.1.100
gateway 192.168.1.1
netmask 255.255.255.0

Obviously replace the address, gateway and netmask with your specific network settings. You may also wish to alter the eth0 adapter to mirror the wlan0 adapter with the same address etc.

Install mono

Finally time to install something. This is the easy part. To install mono just enter the following

sudo apt-get install mono-complete

Install Git tools

Time to install GIT.

sudo apt-get install git

Setup VNC

Install VNCServer using

sudo apt-get install tightvncserver

Now run tightvnsserver and note the number supplied for the desktop for connection from the client machine.

Raspberry Pi A+

The Raspberry Pi A+ has a single USB port (excluding the USB power socket) and no Ethernet port, which is a bit of a pain if trying to setup WiFi and having problems getting the configuration right (especially as I don’t have a powered USB hub to help me out).

Anyway after a lot of hassle here’s the configuration for the Raspberry Pi A+ running Wheezy Raspbian 7. The USB WiFi device I’m using is a WiPi dongle.

Let’s begin with the /etc/network/interfaces file, mine looks like this

auto lo
iface lo inet loopback

auto wlan0
allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet static

address 192.168.1.2
gateway 192.168.1.
netmask 255.255.255.0

obviously the above is setup with a static address, if you want to use a dynamic address change the static to dhcp and remove the address gateway and netmask (to tidy the config up).

Next we need to amend the /etc/wpa_supplicant/wpa_supplicant.conf file, mine looks like this

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
ssid="The Router SSID"
psk="The Router Password"
proto=RSN
key_mgmt=WPA-PSK
pairwise=CCMP TKIP
group=CCMP TKIP
}

The above configures for WPA2 security (use WPA for WPA1).