Useful procedures on Ubuntu

Enable root ssh login on Ubuntu 14.04

edit /etc/ssh/sshd_config to make sure the following:

     PermitRootLogin yes

if want to allow password log in, then add the following line as well 

     PasswordAuthentication yes

for root user, there must be a password generated for root.  

Restart the ssh service

     service ssh restart 

Change em1 to eth0

sudo apt-get remove biosdevname

sudo update-initramfs -u 

on ubuntu 15.10 do the following:

edit /etc/default/grub change

   GRUB_CMDLINE_LINUX_DEFAULT="net.ifnames=0" 

run this command:

   grub-mkconfig -o /boot/grub/grub.cfg

on ubuntu 16.04 do the following:

edit /etc/default/grub change

   GRUB_CMDLINE_LINUX="net.ifnames=0"

run this command: 

   grub-mkconfig -o /boot/grub/grub.cfg 

reboot the system 

Kill processes in Ubuntu by name

kill $(pgrep someprogram)

killall -v someprogram

pkill someprogram

kill `ps -ef | grep someprogram | grep -v grep | awk ‘{print $2}’`

How to setup Pydio on iOS devices

Pydio is a free app for mobile devices to access the ftp accounts. You can find it for both iOS and android devices. Once you install the app onto your mobile devices, follow the steps below to configure it, the example below assumes that your account is called "churchdocs" and the FTP address is www.yourorg.com

    1. Click on the settings icon at the top left.

    2. Click on the + sign at the top right to add a new ftp account:

    3. Input the following information for each field:

        Server address: https://webftp.dreamhost.com

        User name: churchdocs

        User password: <<the password>>

        Label: RCCCDocs <<this should be something meaningful to you>>

        Trust SSL Certificate: On

        Legacy Server (< 4.0): Off

        WebFTP Setup: On

        FTP Address: www.yourorg.com

        FTP Port: 21

        FTP Secure: Off

        FTP Active: Off

    4. Once you input all the above information, click on Save button at the top right.

    5. Now you should have an entry, on the startup page, from this point on, you should be able to just click on that entry to see the contents in the account. On mobile devices, you can view documents and also upload.

Add service daemon to Ubuntu

1. Create a script in /etc/init.d, say we have it named as awesome_script.sh
2. Make the script executable, chmod +x awesome_script.sh
3. Make the daemon starts automatically when system starts
• sudo update-rc.d awesome_script.sh defaults
4. Remove the daemon:
• sudo update-rc.d -f awesome_script.sh remove

Useful Linux Commands

1. lsusb - list all usb ports
2. lsmod - list loaded modules
3. modprobe <module name> - load a module
4. modprobe -r <module name> - unload a module
5. delete all the files in the directory or subdirectory matches the pattern

rm -- **/*.o

or 

find . -type f -name '*.o' -delete