What's the optional lsb-core package

The lsb_release command displays identifying information about your Linux distribution (like Ubuntu, Debian, or CentOS) and its compatibility with the Linux Standard Base (LSB). [1, 2]

Common ways to use it include:

• lsb_release -a: Displays all available information (distributor ID, description, release number, and codename).
• lsb_release -cs: Displays only the short distribution codename (e.g., jammy or focal). This is often used in automated scripts or repository installations to pull the correct software packages.

Alternative methods include: 1) cat /etc/os-release, 2) hostnamectl, 3) uname -a

 

Run:

$ lsb_release -a
No LSB modules are available.
Distributor ID:    Ubuntu
Description:    Ubuntu 25.10
Release:    25.10
Codename:    questing
 

The output means that your Linux system does not have the standard "Linux Standard Base" compatibility software installed, but it is completely normal and safe to ignore.

The lsb_release command is a tool used to print specific details about your Linux distribution. 

Why you see this message

• Missing Compatibility Layer: The message "No LSB modules are available" simply means the optional lsb-core package is missing from your system.
• Harmless Informational Notice: It is not an error message, and it does not mean your computer is broken or missing critical system files.  

Better alternatives to check your system version

Most modern Linux distributions are moving away from LSB. If you want to check your OS version without any warnings, you can use these cleaner command alternatives: [1]

• cat /etc/os-release (Works on almost all modern Linux systems)
• hostnamectl (Works on any system using systemd) [1, 2, 3]

To remove "No LSB modules are available", on Ubuntu/Debian: Run sudo apt install lsb-core 

However, it's not necessary.

 

The lsb-core package is a compatibility layer that provides a standardized environment for third-party software, ensuring that a program built for one Linux distribution can run on another without issues. [1, 2]

Think of it as a bridge: it provides a predictable set of core system libraries, command-line utilities, and directory structures that outside software vendors rely on. [1, 2, 3, 4]

What exactly is inside it?

If you choose to install lsb-core, it sets up several vital components:

• Standard System Libraries: Links to essential baseline code structures (like glibc and basic C/C++ libraries) that software binaries expect to find. [1, 2]
• Crucial Commands: Standardized versions of basic terminal commands (like PAX or m4) that might differ slightly across flavors of Linux. []
• File System Standards: Rules ensuring that critical system paths and configurations sit exactly where third-party apps expect them to be. [, 2]

Why is it labeled "Optional"?

Modern Linux distributions (like Ubuntu and Debian) no longer require it for their daily operations, which is why it isn't pre-installed by default. [1, 2]

Most distributions now prefer lightweight, modern alignment methods (like the /etc/os-release file) rather than maintaining the heavy, older LSB software stack. [1]

Do you actually need to install it?

• 99% of the time, NO: Your system works perfectly fine without it.
• The exception: You only need to install it if you are trying to run specific, proprietary, or legacy enterprise software (such as older commercial databases, specific Epson/HP printer drivers, or certain network tools) that explicitly state they depend on lsb-core to run. 

 

About "Codename: questing"

This refers to the developmental codename for Ubuntu 25.10 (officially released as Questing Quokka in late 2025). [1, 2]

In the Linux and software development world, codenames are used to identify pre-release versions of operating systems before they are finalized and given their official version numbers. [1]

Here are a few quick things to know about it:

• What it is: A developmental (or "nightly") snapshot of Ubuntu Linux. You will usually see this inside the terminal or system settings when using the operating system before it reached its stable, official release. [1]
• The Mascot: Canonical uses sequential alphabetical naming for their releases. This specific one used the Quokka, a small Australian marsupial, as its mascot. [1]
• Status: The Questing development cycle featured major updates like upgrading to GNOME 49 and removing legacy Xorg session support.

 

Alternative ways to show system information

1) 

$ cat /etc/os-release
PRETTY_NAME="Ubuntu 25.10"
NAME="Ubuntu"
VERSION_ID="25.10"
VERSION="25.10 (Questing Quokka)"
VERSION_CODENAME=questing
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=questing
LOGO=ubuntu-logo

2)

$ hostnamectl
 Static hostname: ...
       Icon name: computer-vm
         Chassis: vm 🖴
      Machine ID: ...
         Boot ID: ...
    AF_VSOCK CID: 1
  Virtualization: kvm
Operating System: Ubuntu 25.10                    
          Kernel: Linux 6.17.0-35-generic
    Architecture: x86-64
 Hardware Vendor: RDO
  Hardware Model: OpenStack Compute
Firmware Version: 1.16.3-5.el9.alma.1
   Firmware Date: Sun 2023-11-05
    Firmware Age: 2y 7month 3w 2d 

3)

# uname -a
Linux ${host-name} 6.17.0-35-generic #35-Ubuntu SMP PREEMPT_DYNAMIC Tue May 26 13:10:28 UTC 2026 x86_64 GNU/Linux