I just got my first Raspberry Pi and read a lot of guides on how to set it up but I’ll think I will write this down myself to have as a future reference. This is done with OS X 10.8.
This will set up a Raspberry Pi model B to run Raspbian and have the file system on a USB device instead of running on sensitive SD-Cards.
There are two reasons to do this. As I mentioned the SD-Cards are more sensitive to power breaks and USB-devices and you can end up with a corrupt file system if you are unfortunate.
The second reason is write speed, USB are faster so you end up with a overall faster RPi if you run a lot disc io operations.
What you need:
- Raspberry Pi Model B
- SD-Card (at least 2GB)
- USB device (pen, flash memory, hard drive etc)
Start off by downloading Raspbian here >>
Unzip the downloaded file.
Insert the SD-card into your computer and find out it’s location (open Disc Utility and running a check on it will display the location). In my case the location is /dev/disk2.
#Unmount it diskutil unmountDisk /dev/disk2 #Flash it with the unzipped image #this will take some time. sudo dd bs=1m if=~/Downloads/2013-02-09-wheezy-raspbian.img of=/dev/disk2
The next step is to insert the SD-card and your empty USB-device into the RPi and start it.
I don’t have a monitor to spare so I just SSH into it to set everything up. Find its IP (download Pi Finder to do that if you cant login to your router or run arp -a to find it’s IP).
And then SSH into it from your computer.
ssh firstname.lastname@example.org #The default password is "raspberry"
Now we’re in!
to set up timezone, locales etc.
Now it’s time to copy everything from your SD to the USB-device and instructing the RPi to use it as the root file system.
At the same time we write protect the SD-card to be sure that nothing gets written to it.
The actual booting will be done from the SD but after the boot you can remove it if you like.
#Find USB location. Close to the end of the output you'll find your USB device with something like sda:sda1 dmesg #When you have your USB location, copy everything from the SD-Card to it. Change sda1 to whatever yours is. This takes a while sudo dd if=/dev/mmcblk0p2 of=/dev/sda1 bs=512 #Time to tell the RPi to make the root partition the USB device. Change the line where it says root=/dev/mmcblk0p2 to root=/dev/sda1 sudo nano /boot/cmdline.txt #Next step is to point /dev/sda1 to /. You do that by editing /etc/fstab. sudo nano /etc/fstab
It should look like this:
proc /proc proc defaults 0 0 /dev/mmcblk0p1 /boot vfat defaults,ro 0 2 #/dev/mmcblk0p2 / ext4 defaults,noatime 0 1 /dev/sda1 / ext4 defaults,noatime 0 1
You do three things here. First you make /boot read only. Second you comment out the SD-Card pointing to / and last you make the USB device point to /.
Now restart. (sudo reboot)
Connect to it again and if you run “df -h” you see something like this:
The USB-device only has a total size of 1,8GB.
Lets change that and take advantage of it’s full capacity.
sudo resize2fs /dev/sda1
Now we’re done and can start playing around.