Wednesday, February 28, 2024

Enable/Disable wayland

==

// To check whether wayland / X11 

$ echo $XDG_SESSION_TYPE

x11

==
// To update wayland / x11

$ sudo gvim /etc/gdm3/custom.conf 

  // edit the line 

// this means x11

WaylandEnable=false


// and this means wayland

WaylandEnable=true

==

// To check after update - after reboot 

$ echo $XDG_SESSION_TYPE

==

Monday, February 19, 2024

syslog vs dmesg

Understanding /var/log/syslog and its Relation to dmesg

Both /var/log/syslog and dmesg play crucial roles in logging system activity on Linux-based systems, but they have distinct purposes and relationships. Here's a breakdown:

What is /var/log/syslog?

  • This file acts as a central repository for various system logs originating from diverse sources like:
    • Users & applications
    • Background services (daemons)
    • System startup and shutdown processes
    • Kernel messages (after the system is fully booted)
  • Syslog offers flexibility by allowing different log messages to be directed to specific log files within the /var/log directory based on predefined rules.
  • This categorization facilitates targeted troubleshooting for specific areas of the system.

What is dmesg?

  • Dmesg is a command-line tool that displays the contents of the kernel's ring buffer, a temporary storage for early boot messages and kernel-related activity.
  • This buffer is volatile and resets upon system reboot, meaning dmesg only shows currently ongoing kernel activity.
  • Dmesg isn't a file; it's a real-time snapshot of the kernel ring buffer.

Relationship between /var/log/syslog and dmesg:

  • While syslog captures various system logs, dmesg focuses specifically on kernel messages.
  • Early boot messages, before syslog starts, are only accessible through dmesg.
  • Once syslog is operational, kernel messages are also directed to /var/log/syslog by default.
  • So, dmesg offers a real-time glimpse of kernel activity, while /var/log/syslog provides a more comprehensive historical record of various system events, including kernel messages.

Key differences:

Feature/var/log/syslogdmesg
ScopeDiverse system logsKernel messages
PersistencePersistent across rebootsVolatile, resets on reboot
Real-time viewNot directlyYes
Specific fileYes (individual files for categories)No (command-line tool)


Note: I got the above from google gemini while looking about syslog and dmesg.

Tuesday, November 28, 2023

To setup default kernel in Linux(Fedora)

To setup default kernel in Linux(Fedora):

$ sudo grubby --info=ALL | grep -E "^kernel|^index"
index=0
kernel="/boot/vmlinuz-6.5.5-200.fc38.x86_64"
index=1
kernel="/boot/vmlinuz-6.2.15-100.fc36.x86_64"
index=2
kernel="/boot/vmlinuz-5.17.12-100.fc34.x86_64"
index=3
kernel="/boot/vmlinuz-0-rescue-eeca1c676989405b94bedc847e363048"
index=4
kernel="/boot/memtest86+x64.bin"


$ sudo grubby --set-default-index=2
The default is /boot/loader/entries/eeca1c676989405b94bedc847e363048-5.17.12-100.fc34.x86_64.conf with index 2 and kernel /boot/vmlinuz-5.17.12-100.fc34.x86_64

$ sudo grubby --default-title
Fedora (5.17.12-100.fc34.x86_64) 34 (Workstation Edition)
 

 

 

Monday, November 6, 2023

Software version and end-of-life info.

Software version information

"End-of-life (EOL) and support information is often hard to track, or very badly presented. endoflife.date documents EOL dates and support lifecycles for various products."


https://endoflife.date/


For eg, kubernetes related info. here :

https://endoflife.date/kubernetes

 

Thursday, September 21, 2023

Getting 2FA codes in desktop (and avoid your mobile)

 

Oftentimes I need to pickup my mobile to get the 2FA codes for different accounts.

There should be a simple solution to get 2FA in your desktop.
It is authenticator.cc  & it is open source :) :)

--

Open your mobile and open google authenticator app.  (You may have different app).
Click on export and select the accounts you want to export.
On clicking next, it shows a QR code. 

Screenshot the QR code and send it to yourself (like email/Whatsapp).
--

Now it is the time to get 2FA authenticator codes in your desktop browser.
Visit authenticator.cc and install the addon (in your browser like chrome, firefox, edge)


Click on the addon installed and then click on scan. It will ask for access to all the websites.
For time being give this permission. Now, scan the QR code obtained from above.

That's it, you'll have all QR codes availble in your desktop.

No need to grab the mobile to get 2FA codes.


Note: Remove the permission given (to access all data) using "manage addon".

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