User management

Reference: http://blog.csdn.net/sin90lzc/article/details/7525670

Add new user

sudo adduser username

Reset password when first login

sudo passwd -e username

Delete user

sudo userdel username

Check user details

finger user4

Add user and add into new group 

useradd –g users user1

Add user group UID=888

groupadd –g 888 users

Add user1 into group users

gpasswd –a user1 users

Remove user1 from group users

gpasswd –d user1 users

Rename group

groupmod –n usersold usersnew

Delete group

groupdel users

Add to sudoer

Switch to root

visudo

Add one line under root  ALL=(ALL)    ALL1

newuser ALL=(ALL)     ALL1

Save

Disk partition and mounting

Reference: http://www.cnblogs.com/avril/archive/2010/03/23/1692783.html

Check disk status

sudo fdisk -l

Operate on certain disk

sudo fdisk /dev/sdb

New partition

n

Write changes

w

Format partition

sudo mkfs -t ext3 /dev/sdb1

St label for partition

sudo e2label /dev/sdb1 /backup

Set mount location

sudo mkdir /backup

Set auto mount

sudo vim /etc/fstab

add

LABEL=/backup   /backup      ext3        defaults        1       2

Reboot and check

df -h

Remote SSH

Reference: http://blog.csdn.net/zht666/article/details/9340633

Check whether ssh has installed

ps -e|grep ssh

Install ssh-client

sudo apt-get install openssh-client

Install ssh-server

sudo apt-get install openssh-server

start service

sudo /etc/init.d/ssh start

Configure

sudo gedit /etc/ssh/sshd_config

Restart ssh

sudo /etc/init.d/ssh restart

connect using the format of: ssh account@IP

ssh test@192.168.135.249

autostart when boot

systemctl enable ssh.service

Remote Desktop

Reference from: https://jingyan.baidu.com/article/48206aeaab3550216bd6b310.html

sudo apt-get install  vnc4server

使用在/usr/share/applications目录下打开“桌面共享”选项，桌面共享选项中必须要开启共享，自己根据需要选择是否需要每次连接提示、密码等

以上步骤完成后，在安装WINDOWS操作系统的电脑中打开VNC Viewer连接Ubantu会提示安全错误 。

Ubantu安装 dconf-editor 软件，输入命令

sudo apt-get install dconf-editor

用Dconf-editor调整，并访问如下配置路径：

org > gnome > desktop > remote-access

取消钩选 “requlre-encryption”属性。

在安装WINDOWS操作系统的电脑中打开VNC Viewer，出现如下提示，恭喜大功告成。

Remote Desktop for multiple users

sudo apt-get install xrdp

to avoid authentication prompt for color device 

sudo nano /etc/polkit-1/localauthority/50-local.d/45-allow-colord.pkla

paste 

[Allow Colord all Users]
Identity=unix-user:*
Action=org.freedesktop.color-manager.create-device;org.freedesktop.color-manager.create-profile;org.freedesktop.color-manager.delete-device;org.freedesktop.color-manager.delete-profile;org.freedesktop.color-manager.modify-device;org.freedesktop.color-manager.modify-profile
ResultAny=no
ResultInactive=no
ResultActive=yes

save and reboot

For other desktop environments

Reference from: http://blog.csdn.net/u011428870/article/details/73611684

Install Mate-desktop

sudo apt-add-repository ppa:ubuntu-mate-dev/xenial-mate
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install mate-desktop-environment mate-notification-daemon

Install xrdp

sudo apt-get install xrdp
echo mate-session > ~/.xsession
sudo sed -i.bak '/fi/a #xrdp multiple users configuration \n mate-session \n' /etc/xrdp/startwm.sh
sudo service xrdp restart

为了使每次连接到同一个session，可以修改xrdp.ini：

sudo gedit /etc/xrdp/xrdp.ini

在[xrdp1]中，修改port=-1为port=ask-1，接着在下一次重新连接时，会发现最下面出现了port一栏，一开始是-1，登陆时记住自己的port，退出再次登陆将port数值改为自己的，就可以继续上次关闭时的状态。

Mount Windows folder

For nfs based file system, following utility is required

sudo apt-get install nfs-common

To mount a Cifs file system, install the following utility

sudo apt install cifs-utils

To mount a path

mount -t cifs //128.208.221.39 /mnt/desktop2 --verbose -o user=li,password=v

mount as user

sudo mount -t cifs //128.208.221.24/OAI-Derived-Data-and-Results /mnt/V --verbose -o user=li,password=,uid=nobody

or edit the files

sudo nano /etc/fstab

add the paths at the end

//128.208.221.39/Ftensorflow /mnt/desktop2/Ftensorflow cifs username=li,password=v,uid=nobody,iocharset=utf8,noperm 0 0

sudo mount -a

Configure system

setting editor

sudo apt-get install dconf-editor

org –> gnome –> nautilus –> preferences and choose always-use-location-entry

Hide/show dock menu

sudo apt-get install gnome-tweak-tool

alt+f2, r, enter

gnome-tweaks->extension->ubuntu dock

Fix ip

show current connections

nmcli con show

to restore to auto 

nmcli con mod "Wired connection 2"
  ipv4.addresses ""
  ipv4.gateway ""
  ipv4.dns ""
  ipv4.dns-search ""
  ipv4.method "auto"