Today it is time to use Samba for USB Drives sharing.

Mounting USB Drive

1. Create new directory where your drive will be mounted

sudo mkdir /media/usbHDD
sudo chmod 744 /media/usbHDD

2. List your storage devices and save UUID of your drive

ls -l /dev/disk/by-uuid/

(Update) more readable command:

sudo lsblk -o UUID,NAME,FSTYPE,SIZE,MOUNTPOINT,LABEL,MODEL
or
sudo blkid

3. Mount that drive to /media/usbHDD, use proper user and group (uid, guid), adjust drive path

sudo mount -o uid=pi,gid=pi /dev/sda1 /media/usb

4. Edit fstab

sudo nano /etc/fstab

and add line with UUID of your drive

UUID=18A9-9943 /media/usbHDD vfat auto,nofail,noatime,users,rw 0 0

5. Verify if drive is mounted

ls -l /media/usbHDD

restart and verify if drive is mounted after reboot

sudo reboot now
ls -l /media/usbHDD

Update:

If you have problems with auto mount you may need to install:

sudo apt-get install exfat-fuse 
or
sudo apt-get install ntfs-3g

You may also need to change partition type in command in fstab file from vfat to ntfs

Installing Samba

The process of installation is very simple

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install samba samba-common-bin

Czytaj więcej

In this post I’ll gather all useful commands that I used during my experiments with RPi

Commands:

Lists all attached bulk storage devices

lsblk

List all drives by uuid

ls -l /dev/disk/by-uuid/

Mount drive

sudo mount -o uid=pi,gid=pi /dev/sda1 /media/usb 

you have to use uid and gid in order to delete add new devices.

Automount drive at start-up

sudo nano /etc/fstab

and add

UUID=18A9-9943 /media/usb vfat auto,nofail,noatime,users,rw 0 0

The “nofail” option allows the boot process to proceed if the drive is not plugged in. The “noatime” option stops the file access time being updated every time a file is read from the USB stick. This helps improve performance.
Czytaj więcej

I’m always looking for this commands when I need to install latest Java 8 JDK on my RPi, so I’m adding them here just in case I’ll need to use them again.

Unfortunately default Raspbian repository contains old Java version 1.8.0_65-b17 while the latest (when I’m writing this post) is 1.8.0_151-b12.

Installation

First install dirmngr:

 sudo apt-get install dirmngr

Second add deb repositories and key:

echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" | sudo tee /etc/apt/sources.list.d/webupd8team-java.list
echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" | sudo tee -a /etc/apt/sources.list.d/webupd8team-java.list
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886

Warning! If you add xentail repositories (as many RPi forums and other pages state) you’ll end up with old 1.8.0_65 version, you must be using trusty repositories in order to install latest Java version.

Update repositories:

sudo apt-get update

Install Java installer:

 sudo apt-get install oracle-java8-jdk 

Verify Java version

To be 100% sure I have proper version of Java I use basic command:

java -version

Remove old Java

In case you have old Java 8 JDK

sudo apt-get remove --purge oracle-java8-jdk

Sources

Remove Java
Default Java installation
trusty repositories of Java 8 JDK

Basically I wanted to test how fast my RPi will heat up under stress with or without heat sinks

How to perform stress test

It is easy with stress application.

Install:

sudo apt-get install stress 

Stress test:

sudo stress --cpu 4

it will span 4 processes that will execute on each of RPi core calculating sqrt function (source).

Constantly measure CPU temperature

Command:

watch -n 1 /opt/vc/bin/vcgencmd measure_temp

This command will print cpu temperature on console each 1 second.

CPU utilisation

You can observe how 4 stress processes are utilising cpu with command:

top

Radiator tests

Cheapest small aluminium radiators under 0.24$ per lot: link

No heat sinks:

• idle: around 50 C
• under stress: up to 82 C
• response on air flow: low decreases maximum temperature by 2-3 C

With heat sinks:

• idle: around 44 C
• under stress: up to 77 C
• response on air flow: good decreases maximum temperature by 7-8 C

Conclusion

I’m a bit disappointed with those small heat sinks, expecting that they’ll lower temperatures more drastically. Using fan that will blows air on them will give better results.

Simple as it is:

date +%s

The fastest way to compare two files in vimdiff is firstly open:

vimdiff <file1.bin> <file2.bin>

Displaying content in hex format:

:%!xxd

to switch to other pane:

Ctrl + W

This is a quick  solluion how to replace windows style line endings <CRLF> to unix style <LF>

In vim type:

:w ++f=unix

Czytaj więcej