*******ORACLE Apps DBA & ORACLE DBA Blog*******

Wednesday, 10 June 2026

Windows Subsystem for Linux (WSL)

Windows Subsystem for Linux (WSL) is a feature of Windows that allows you to run a Linux environment directly on Windows without installing a separate virtual machine or dual-booting your computer.

WSL enables developers, system administrators, and DBAs to use Linux command-line tools, scripts, and applications alongside Windows.

Why Use WSL?

WSL allows you to:

Run Linux distributions such as Ubuntu, Debian, and Oracle Linux.
Use Linux commands and shell scripting.
Install development tools (Git, Python, Java, Node.js).
Manage databases such as PostgreSQL and MySQL.
Run automation scripts.
Access Windows files from Linux and vice versa.

For Oracle DBAs and EBS administrators, WSL is useful for learning Linux administration, shell scripting, automation, Ansible, Git, and database tools without needing a dedicated Linux server.

WSL Architecture

WSL 1

Translates Linux system calls into Windows system calls.
Lower resource consumption.
Faster access to Windows files.
Limited compatibility.

WSL 2

Uses a real Linux kernel.
Better performance and compatibility.
Supports Docker and containerized applications.
Recommended for most users.

Prerequisites

Windows 10 (Version 2004+) or Windows 11
Administrator privileges
Virtualization enabled in BIOS

Check virtualization: Open Windows PowerShell

Windows PowerShell

Install the latest PowerShell for new features and improvements! https://aka.ms/PSWindows

PS C:\Users\USER>systeminfo

Install WSL2 (Windows Subsystem for Linux) - Recommended
Open PowerShell as Administrator and run:
PS C:\Users\USER> wsl
Windows Subsystem for Linux must be updated to the latest version to proceed. You can update by running 'wsl.exe --update'.
For more information please visit https://aka.ms/wslinstall

Press any key to install Windows Subsystem for Linux.
Press CTRL-C or close this window to cancel.
This prompt will time out in 60 seconds.
The requested operation requires elevation.
Downloading: Windows Subsystem for Linux 2.7.3
Installing: Windows Subsystem for Linux 2.7.3
Windows Subsystem for Linux 2.7.3 has been installed.
The operation completed successfully.
Windows Subsystem for Linux has no installed distributions.
You can resolve this by installing a distribution with the instructions below:

Use 'wsl.exe --list --online' to list available distributions
and 'wsl.exe --install <Distro>' to install.
PS C:\Users\USER> wsl.exe --list --online
The following is a list of valid distributions that can be installed.
Install using 'wsl.exe --install <Distro>'.

NAME                            FRIENDLY NAME
Ubuntu                          Ubuntu
Ubuntu-26.04                    Ubuntu 26.04 LTS
Ubuntu-24.04                    Ubuntu 24.04 LTS
Ubuntu-22.04                    Ubuntu 22.04 LTS
openSUSE-Tumbleweed             openSUSE Tumbleweed
openSUSE-Leap-16.0              openSUSE Leap 16.0
SUSE-Linux-Enterprise-15-SP7    SUSE Linux Enterprise 15 SP7
SUSE-Linux-Enterprise-16.0      SUSE Linux Enterprise 16.0
kali-linux                      Kali Linux Rolling
Debian                          Debian GNU/Linux
AlmaLinux-8                     AlmaLinux OS 8
AlmaLinux-9                     AlmaLinux OS 9
AlmaLinux-Kitten-10             AlmaLinux OS Kitten 10
AlmaLinux-10                    AlmaLinux OS 10
archlinux                       Arch Linux
FedoraLinux-44                  Fedora Linux 44
FedoraLinux-43                  Fedora Linux 43
eLxr                            eLxr 12.12.0.0 GNU/Linux
OracleLinux_7_9                 Oracle Linux 7.9
OracleLinux_8_10                Oracle Linux 8.10
OracleLinux_9_5                 Oracle Linux 9.5
SUSE-Linux-Enterprise-15-SP6    SUSE Linux Enterprise 15 SP6
PS C:\Users\USER> wsl.exe --install Ubuntu-26.04
Downloading: Ubuntu 26.04 LTS
Installing: Ubuntu 26.04 LTS
Distribution successfully installed. It can be launched via 'wsl.exe -d Ubuntu-26.04'
Launching Ubuntu-26.04...
Provisioning the new WSL instance Ubuntu-26.04
This might take a while...
Create a default Unix user account: ubuntu
New password:
Retype new password:
passwd: password updated successfully
usermod: no changes
Help improve Ubuntu!

Help us improve Ubuntu features and compatibility by sharing system reports with Canonical.
Reports are sent anonymously and do not contain any personal data.
For legal details, please visit: https://ubuntu.com/legal/systems-information-notice

We will save your answer to Windows and will only ask you once.

Would you like to opt-in to platform metrics collection (Y/n)? To see an example of the data collected, enter 'e'.
[Y/n/e]: n
Verify Installation
After reboot:
PS C:\Users\USER> wsl --version
WSL version: 2.7.3.0
Kernel version: 6.6.114.1-1
WSLg version: 1.0.73
MSRDC version: 1.2.6676
Direct3D version: 1.611.1-81528511
DXCore version: 10.0.26100.1-240331-1435.ge-release
Windows version: 10.0.26200.8457
PS C:\Users\USER> wsl --status
Default Distribution: Ubuntu-26.04
Default Version: 2
Check installed distributions:
PS C:\Users\USER> wsl -l -v
  NAME            STATE           VERSION
* Ubuntu-26.04    Running         2
Start Linux
PS C:\Users\USER> wsl
ubuntu@Amit-Gupta:/mnt/c/Users/USER$ sudo apt update
[sudo: authenticate] Password:
Get:1 http://security.ubuntu.com/ubuntu resolute-security InRelease [137 kB]
Get:2 http://archive.ubuntu.com/ubuntu resolute InRelease [136 kB]
Get:3 http://security.ubuntu.com/ubuntu resolute-security/main amd64 Packages [201 kB]
Get:4 http://security.ubuntu.com/ubuntu resolute-security/main Translation-en [54.0 kB]
Get:5 http://security.ubuntu.com/ubuntu resolute-security/main amd64 Components [31.1 kB]
Get:6 http://security.ubuntu.com/ubuntu resolute-security/main amd64 c-n-f Metadata [3312 B]
Get:7 http://security.ubuntu.com/ubuntu resolute-security/universe amd64 Packages [103 kB]
Get:8 http://security.ubuntu.com/ubuntu resolute-security/universe Translation-en [32.1 kB]
Get:9 http://security.ubuntu.com/ubuntu resolute-security/universe amd64 Components [42.8 kB]
Get:10 http://security.ubuntu.com/ubuntu resolute-security/universe amd64 c-n-f Metadata [2788 B]
Get:11 http://security.ubuntu.com/ubuntu resolute-security/restricted amd64 Packages [201 kB]
Get:12 http://security.ubuntu.com/ubuntu resolute-security/restricted Translation-en [35.1 kB]
Get:13 http://security.ubuntu.com/ubuntu resolute-security/restricted amd64 c-n-f Metadata [396 B]
Get:14 http://security.ubuntu.com/ubuntu resolute-security/multiverse amd64 Components [212 B]
Get:15 http://security.ubuntu.com/ubuntu resolute-security/multiverse amd64 c-n-f Metadata [120 B]
Get:16 http://archive.ubuntu.com/ubuntu resolute-updates InRelease [137 kB]
Get:17 http://archive.ubuntu.com/ubuntu resolute-backports InRelease [136 kB]
Get:18 http://archive.ubuntu.com/ubuntu resolute/main amd64 Packages [1480 kB]
Get:19 http://archive.ubuntu.com/ubuntu resolute/main Translation-en [524 kB]
Get:20 http://archive.ubuntu.com/ubuntu resolute/main amd64 Components [395 kB]
Get:21 http://archive.ubuntu.com/ubuntu resolute/main amd64 c-n-f Metadata [32.4 kB]
Get:22 http://archive.ubuntu.com/ubuntu resolute/universe amd64 Packages [16.0 MB]
Get:23 http://archive.ubuntu.com/ubuntu resolute/universe Translation-en [6329 kB]
Get:24 http://archive.ubuntu.com/ubuntu resolute/universe amd64 Components [4556 kB]
Get:25 http://archive.ubuntu.com/ubuntu resolute/universe amd64 c-n-f Metadata [313 kB]
Get:26 http://archive.ubuntu.com/ubuntu resolute/restricted amd64 Packages [152 kB]
Get:27 http://archive.ubuntu.com/ubuntu resolute/restricted Translation-en [25.8 kB]
Get:28 http://archive.ubuntu.com/ubuntu resolute/restricted amd64 Components [556 B]
Get:29 http://archive.ubuntu.com/ubuntu resolute/multiverse amd64 Packages [290 kB]
Get:30 http://archive.ubuntu.com/ubuntu resolute/multiverse Translation-en [127 kB]
Get:31 http://archive.ubuntu.com/ubuntu resolute/multiverse amd64 Components [50.0 kB]
Get:32 http://archive.ubuntu.com/ubuntu resolute/multiverse amd64 c-n-f Metadata [8276 B]
Get:33 http://archive.ubuntu.com/ubuntu resolute-updates/main amd64 Packages [208 kB]
Get:34 http://archive.ubuntu.com/ubuntu resolute-updates/main Translation-en [55.8 kB]
Get:35 http://archive.ubuntu.com/ubuntu resolute-updates/main amd64 Components [37.2 kB]
Get:36 http://archive.ubuntu.com/ubuntu resolute-updates/main amd64 c-n-f Metadata [3428 B]
Get:37 http://archive.ubuntu.com/ubuntu resolute-updates/universe amd64 Packages [107 kB]
Get:38 http://archive.ubuntu.com/ubuntu resolute-updates/universe Translation-en [33.4 kB]
Get:39 http://archive.ubuntu.com/ubuntu resolute-updates/universe amd64 Components [49.0 kB]
Get:40 http://archive.ubuntu.com/ubuntu resolute-updates/universe amd64 c-n-f Metadata [2676 B]
Get:41 http://archive.ubuntu.com/ubuntu resolute-updates/restricted amd64 Packages [201 kB]
Get:42 http://archive.ubuntu.com/ubuntu resolute-updates/restricted Translation-en [35.1 kB]
Get:43 http://archive.ubuntu.com/ubuntu resolute-updates/restricted amd64 c-n-f Metadata [392 B]
Get:44 http://archive.ubuntu.com/ubuntu resolute-updates/multiverse amd64 Packages [3328 B]
Get:45 http://archive.ubuntu.com/ubuntu resolute-updates/multiverse Translation-en [772 B]
Get:46 http://archive.ubuntu.com/ubuntu resolute-updates/multiverse amd64 Components [216 B]
Get:47 http://archive.ubuntu.com/ubuntu resolute-updates/multiverse amd64 c-n-f Metadata [256 B]
Get:48 http://archive.ubuntu.com/ubuntu resolute-backports/main amd64 Components [212 B]
Get:49 http://archive.ubuntu.com/ubuntu resolute-backports/main amd64 c-n-f Metadata [112 B]
Get:50 http://archive.ubuntu.com/ubuntu resolute-backports/universe amd64 Components [216 B]
Get:51 http://archive.ubuntu.com/ubuntu resolute-backports/universe amd64 c-n-f Metadata [116 B]
Get:52 http://archive.ubuntu.com/ubuntu resolute-backports/restricted amd64 Components [216 B]
Get:53 http://archive.ubuntu.com/ubuntu resolute-backports/restricted amd64 c-n-f Metadata [120 B]
Get:54 http://archive.ubuntu.com/ubuntu resolute-backports/multiverse amd64 Components [216 B]
Get:55 http://archive.ubuntu.com/ubuntu resolute-backports/multiverse amd64 c-n-f Metadata [120 B]
Fetched 32.2 MB in 6s (5033 kB/s)
34 packages can be upgraded. Run 'apt list --upgradable' to see them.
ubuntu@Amit-Gupta:/mnt/c/Users/NICSI$ cd
ubuntu@Amit-Gupta:~$ sudo su -
                                    OR
ubuntu@Amit-Gupta:/mnt/c/Users/USER$ sudo su - (Switch to root User)
Welcome to Ubuntu 26.04 LTS (GNU/Linux 6.6.114.1-microsoft-standard-WSL2 x86_64)

 * Documentation:  https://docs.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/pro

 System information as of Tue Jun  9 10:27:27 UTC 2026

  System load:  0.06                Processes:             37
  Usage of /:   0.1% of 1006.85GB   Users logged in:       0
  Memory usage: 6%                  IPv4 address for eth0: 172.29.53.113
  Swap usage:   0%

This message is shown once a day. To disable it please create the
/root/.hushlogin file.

root@Amit-Gupta:~#
Access Windows Files from Linux
Windows C: drive appears as:
root@Amit-Gupta:~# cd /mnt/c
root@Amit-Gupta:~# cd /mnt/c/Users
root@Amit-Gupta:~# ls
Access Linux Files from Windows
Linux files are stored under:
\\wsl$\
Open File Explorer(Win + E) and enter:
\\wsl$\

PostgreSQL Installation on Ubuntu

PostgreSQL is a powerful open-source relational database management system (RDBMS) known for its reliability, extensibility, and compliance with SQL standards. It is widely used in enterprise applications, data warehousing, web applications, and cloud environments.

This document describes the steps required to install and configure PostgreSQL on an Ubuntu Linux server.

Prerequisites

Before starting the installation, ensure the following:

Ubuntu Server (20.04, 22.04, or later)
Root or sudo privileges
Internet connectivity for package download
Minimum 2 GB RAM and adequate disk space

Step 1: Update System Packages

Update the package repository to ensure the latest package information is available.

root@Amit-Gupta:~# sudo apt update
root@Amit-Gupta:~# sudo apt upgrade -y
root@Amit-Gupta:~# apt install sysstat* -y
root@Amit-Gupta:~# apt install net-tool* -y
root@Amit-Gupta:~# sudo apt install -y wget gnupg2 lsb-release

Download the PostgreSQL GPG Key
wget -qO - https://www.postgresql.org/media/keys/ACCC4CF8.asc
wget downloads files from the internet.
-q runs wget in quiet mode (suppresses output).
-O - sends the downloaded content to standard output (stdout) instead of saving it to a file.
https://www.postgresql.org/media/keys/ACCC4CF8.asc is the official PostgreSQL public signing key.
The pipe (|) sends the downloaded key directly to the next command.
Convert the Key to Binary Format
sudo gpg --dearmor -o /usr/share/keyrings/postgresql.gpg
gpg is the GNU Privacy Guard utility.
--dearmor converts the ASCII-armored key (.asc) into a binary GPG keyring format.
-o /usr/share/keyrings/postgresql.gpg saves the converted key to the specified location.
sudo is required because writing to /usr/share/keyrings requires root privileges.
Result
After execution, the file:
/usr/share/keyrings/postgresql.gpg
is created and contains the PostgreSQL repository's trusted signing key.
Why This Is Required
When you add the PostgreSQL APT repository, Ubuntu uses this key to:
Verify package authenticity.
Ensure packages have not been tampered with.
Establish trust between your server and the PostgreSQL package repository.
root@Amit-Gupta:~# wget -qO - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo gpg --dearmor -o /usr/share/keyrings/postgresql.gpg
Next Step
Add the PostgreSQL repository:root@Amit-Gupta:~# echo "deb [signed-by=/usr/share/keyrings/postgresql.gpg] http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" | sudo tee /etc/apt/sources.list.d/pgdg.list

Step 2: Install PostgreSQL

Install PostgreSQL and additional contributed modules.

root@Amit-Gupta:~# sudo apt install -y postgresql-17

root@Amit-Gupta:~# sudo apt install postgresql postgresql-contrib -y

root@Amit-Gupta:~# sudo apt install -y postgresql-client-17 postgresql-contrib-17

The installation process automatically creates a PostgreSQL service and initializes a default database cluster.

Step 3: Verify Installation

Verify that the PostgreSQL service is running:

root@Amit-Gupta:~# sudo systemctl status postgresql

Check the PostgreSQL version:

root@Amit-Gupta:~# psql --version

psql (PostgreSQL) 17.10 (Ubuntu 17.10-1.pgdg26.04+1)

Step 4: Start and Enable PostgreSQL Service

If the service is not running, start it manually:

root@Amit-Gupta:~# sudo systemctl start postgresql

Enable automatic startup during system boot:

root@Amit-Gupta:~# sudo systemctl enable postgresql

root@Amit-Gupta:~# sudo systemctl status postgresql@17-main.service

Step 5: Connect to PostgreSQL
Switch to the PostgreSQL operating system user:
root@Amit-Gupta:~# sudo -i -u postgres
Access the PostgreSQL command-line interface:
postgres@Amit-Gupta:~$ psql
psql (17.10 (Ubuntu 17.10-1.pgdg26.04+1))
Type "help" for help.

postgres=# \q
Step 6: Create a Database User
Login to PostgreSQL:
root@Amit-Gupta:~# sudo -u postgres psql
Create a new database user:
postgres=# CREATE USER postgres WITH PASSWORD 'postgres';

                        OR

postgres=# ALTER USER postgres PASSWORD 'postgres';
ALTER ROLE
Step 7: Create a Database
Create a new database:
postgres=# CREATE DATABASE appdb OWNER postgres;
Grant privileges:
postgres=# GRANT ALL PRIVILEGES ON DATABASE appdb TO postgres;
Verify database creation:
postgres=# \l
Verify users:
postgres=# \du

postgres=# \q
Step 8: Configure Remote Connections (Optional)
Modify postgresql.conf
Edit the PostgreSQL configuration file:
root@Amit-Gupta:~# sudo vi /etc/postgresql/17/main/postgresql.conf
Locate:
#listen_addresses = 'localhost'
Change to:
listen_addresses = '*'
Modify pg_hba.conf
Edit client authentication settings:
root@Amit-Gupta:~# sudo vi /etc/postgresql/17/main/pg_hba.conf
Add the following entry:
host    all    all    0.0.0.0/0    md5

                    OR

host    all   all     0.0.0.0/0   scram-sha-256
Restart PostgreSQL
root@Amit-Gupta:~# sudo systemctl restart postgresql

Step 9: Configure Firewall
Allow PostgreSQL default port 5432:
root@Amit-Gupta:~# sudo ufw allow 5432/tcp
Verify firewall rules:
root@Amit-Gupta:~# sudo ufw status
root@Amit-Gupta:~# sudo netstat -tulpn | grep 5432
Useful PostgreSQL Commands
Check database list:
postgres=# \l
Connect to a database:
postgres=# \c appdb
Display tables:
postgres=# \dt
Display users:
postgres=# \du
Exit PostgreSQL:
postgres=# \q

PostgreSQL has been successfully installed and configured on Ubuntu. 
The database service is running, users and databases can be created, 
and remote access can be enabled when required. PostgreSQL provides 
a robust platform for enterprise applications, data analytics, and mission-critical 
database workloads.