Posts Tagged ‘cmd’

Generate and Use WiFi passwords via QR code on Linux

Monday, November 17th, 2025

If you’re running a WiFi network for a guest house / AirBNB, a small hotel or an office / home network and you’re tired of telling / dictating guests your long, complicated Wi-Fi password every time they visit, there’s a simple and secure way to share the WiFi name and password by putting the info in a WiFi authentication QR code. With a simple scan from their phone via a QR reader (which iPhones and all modern smartphones have), they can join your network instantly with zero typing.

In short — Why use a QR Code for Wi-Fi?

  • Convenience for guests: No more reading or spelling out your SSID and password.
  • Better security practice: Keep a strong password while still making access easy.
  • Works on most devices: Android and iOS both support Wi-Fi QR codes.

The Wi-Fi QR Code Standard Format

Smartphones understand Wi-Fi QR codes using this format:

WIFI:S:;T:;P:;;

  • S: your Wi-Fi network name (SSID)
  • T: encryption type (WPA, WEP, or nopass)
  • P: your Wi-Fi password
  • Everything ends with ;;

If your SSID or password contains special characters such as ; or \, they must be escaped using a backslash \.

Example:

SSID = WifiNetworkName
Password = @ss;word45123P4?#$!
Type = WPA

The final string becomes:

WIFI:S:WifiNetworkName;T:WPA;P:@ss\;word45123P4?#$!;;

How to Generate the QR Code Locally on Linux

You can generate the QR code locally using qrencode instead of uploading credentials online.

  1. Install qrencode (Debian/Ubuntu):

    # apt update # apt install qrencode

  2. Generate the QR code:

    # qrencode -o wifi-qr.png 'WIFI:S:WifiNetwork;T:WPA;P:P@ss\;word!;;'

    Example with colors and SVG output:

    # qrencode -t svg –foreground=FFFFFF –background=000000 \ -o qr-code.svg –inline –rle -s 10 \ "WIFI:S:MyWiFI;T:WPA;P:<Secret_Pass>;;"

    Use -s to increase size, e.g. -s 10.

  3. Print or share the generated wifi-qr.png.

Alternative: GUI / Desktop Approach

On GNOME-based systems (Ubuntu, Fedora), install the WiFi QR Code GNOME extension.

  • Open quick settings → Wi-Fi → “Show QR Code”
  • Right-click to copy or save for printing

Advanced: Using wifi-qr Tool

The wifi-qr tool provides CLI and GUI Wi-Fi QR generation.

# terminal interface to generate QR
# wifi-qr -t

wifi-qr screenshot

This command prints your current Wi-Fi SSID, encryption type, and password in clear text.

Security Tips

  • Limit where you display the QR
  • Rotate the password when needed
  • Use a guest network instead of your main one
  • Prefer WPA2/WPA3
  • Store QR images safely

How Guests Use the QR Code

  1. Open the phone camera (iOS/Android)
  2. Point it at the QR
  3. Tap “Join” when the Wi-Fi prompt appears

Final Thoughts

Generating a Wi-Fi QR code blends security with usability. Whether using qrencode, a GUI extension, or a website, guests connect instantly with a quick scan – no typing required.

Fix Update KB5060999 Not Installing On Windows 11 Version 23H2/22H2 / Fix windows Update failed

Thursday, July 24th, 2025

fix-Update-KB5060999-Not_Installing_On_Windows_11_Version_23H2_22H2-howto-update-screenshot

 

Recently I've stumbled across a very annoying issue on my work Laptop. Suddenly windows stopped being upadted it took me really long time of hours of researching to find out how to resolve the error:

Fix Update KB5060999 Not Installing On Windows 11 Version 23H2/22H2 / Fix windows Update failed

After a lot of catch / tries I can manage to Find a fix Thanks God! 

Here are the few steps I took to resolve it, first I've taken all the steps pointed at the Complete Guide Windows Problems it took really long time but even thouigh I did not manage to resolve the issue it give a lot of understanding on different ways of how windows components stick together and how to debug and solve errors if such ones occurs. Thus I warmly recommend it to anyone working as HelpDesk support admin within corporation or if you are a Windows specialist who makes a living from resolving weird unexpected Windows errors for some little money.

Once I went through a lot of underwater stones and nothing word finally  I managed to solve it by following these concrete steps:

1. Check logs and find error message / problems in CBS.log

C:\> notepad c:\windows\Logs\CBS\CBS.log

The root of the issue I found there as a repeating error messages is:

"InternalOpenPackage failed for Package_for_KB3025096~31bf3856ad364e35~amd64~~6.4.1.0 [HRESULT = 0x800f0805 – CBS_E_INVALID_PACKAGE]"

 

2. Download from Windows catalog the Update


windows11.0-kb5049624-x64-ndp481_6990e824379adc100fd7895adb30e692697381d7.msu to C:\User\myuser\Downloads

3. Use Winrar or 7Zip to extract the msu in local Directory

E.g.open Administrator command line cmd.exe extract  in lets say in \Users\Username\Downloads\
windows11.0-kb5049624-x64-ndp481_6990e824379adc100fd7895adb30e692697381d7

C:\Users/a768839/Downloads/windows11.0-kb5049624-x64-ndp481_6990e824379adc100fd7895adb30e692697381d7 > dir
WSUSSCAN.cab             

4. Remove old package existing on the Windows 11 OS with the same name using DISM tool with /online /remove-package options

C:\Users\myuser\Downloads\windows11.0-kb5049624-x64-ndp481_6990e824379adc100fd7895adb30e692697381d7>DISM /online /remove-package /packagepath:C:\Users\a768839\Downloads\windows11.0-kb5049624-x64-ndp481_6990e824379adc100fd7895adb30e692697381d7\Windows11.0-KB5049624-x64-NDP481.cab                                                                                                                                                                    Deployment Image Servicing and Management tool                                                                                                                                                                                                                                            Version: 10.0.22621.2792                                                                                                                                                                                                                                                                                                                                           Image Version: 10.0.22631.5335                                                                                                                                                                                                                                                                                                                 Processing 1 of 1 – Removing package Package_for_DotNetRollup_481~31bf3856ad364e35~amd64~~10.0.9294.1                                                                                                                                                                                     [==========================100.0%================]                                                                                                                                                                                                                            
 The operation completed successfully.      

                                                                                                                                                                                                                                              5. Use DISM /online /add-package to manually insatall  windows11.0-kb5049624-x64-ndp481_6990e824379adc100fd7895adb30e692697381d7\Windows11.0-KB5049624-x64-NDP481.cab   
                                             

  Assuming you have already downloaded previously and exctracted the .msu file and you have the .cab file at hand run again as cmd.exe Admin                                                                                                                                                                                       

C:\Users\myuser\Downloads\windows11.0-kb5049624-x64-ndp481_6990e824379adc100fd7895adb30e692697381d7>DISM /online /add-package /packagepath:C:\Users\a768839\Downloads\windows11.0-kb5049624-x64-ndp481_6990e824379adc100fd7895adb30e692697381d7\Windows11.0-KB5049624-x64-NDP481.cab                                                                                                                                                                                           Deployment Image Servicing and Management tool                                                                                                                                                                                                                                            Version: 10.0.22621.2792                                                                                                                                                                                                                                                                                                                                                Image Version: 10.0.22631.5335                                                                                                                                                                                                                                                                                                                  Processing 1 of 1 – Adding package Package_for_DotNetRollup_481~31bf3856ad364e35~amd64~~10.0.9294.1                                                                                                                                                                                       [==========================100.0%==========================]                                                                                                                                                                                                                              The operation completed successfully.    


The idea to remove and install the failing package found in the CBS.log was initially found on                                                                   
 http://datadump.ru/windows-update-error-800f0831/
 

6. Force a Windows chkdsk (Check disk on next restart) to make sure no physical hard drive or some other inode Windows Filesystem errors are there

Within same Admin cmd.exe

C:\Users\myuser\> chkdsk /f C:\


Once command executes reboot the PC and wait for the chkdsk scan to complete and PC to Boot as usual

7. Stop / start wuauserv and do sfc /scannow to refresh some Windows update components

Run following set of commands within Admin cmd

C:\> net stop wuauserv
C:\> command prompt in admin mode
C:\>  dism /online /cleanup-image /startcomponentcleanup
C:\>  sfc /scannow
C:\> restart
C:\> sfc /scannow
C:\> net start wuauserv

8. Download Manually failing update from Windows catalog download site:

As of time of writting this article the URL to download is https://catalog.update.microsoft.com/Search.aspx?q=KB5049624%20%20

C:\Users\myuser\Downloads> dir *.msu
windows11.0-kb5060999-x64_99e39c1cf8a8976d9b3313efb38069876c417f70.msu

9. Run Manually again failing Update from command line

Run cmd as Administrator and exec the file:

C:\Users\myuser\Downloads\windows11.0-kb5060999-x64_99e39c1cf8a8976d9b3313efb38069876c417f70.msu

Wait for the install to complete The computer will need to restart

10. Resync the device to the Computer Domain (mandatory step) only if your PC is part of large organizational Domain

Open Microsoft Store / Company Portal and Sync the device (if necessery)

Settings -> Sync

11. Force the PC to sync itself with remote Global Domain policies (mandatory only if PC is part of Domain)

C:\Users\myuser> gpupdate /force
C:\Users\myuser> repadmin /showrepl

Wait for Synchronization and wait for some time for computer compliancy to get back to normal (Computer compliancy might not be an issue if this is a Personal Windows installation) but for computers part of Larger Windows Domains, where a Domain policy requires a compliancy to set of rules)

To come up with this guide and better understand what is going on to resolve it I have to thank my colleague Eduard for assisting me to read the CBS.log and analyze it and also the following forum thread reading explaining what causes the mysterious windows update Update KB5060999 Not Installing On Windows 11 Version 23H2/22H2 to fail.
 

How to Fix Windows Update Problems: A Complete Guide

Friday, July 11th, 2025

fix-windows-update-problems-howto-picture

Windows Update is essential for keeping your Windows system secure, stable, and up to date to be on track with latest security patches and (for those working in large corporations) for the PC to be compliant to Company / Corporation / Domain security defined policies and standards. However, users often encounter issues like updates failing to install, being stuck at a certain percentage, or causing error messages. Whether you're using Windows 10 or Windows 11, this guide walks you through proven steps to fix Windows Update problems.

Common Symptoms of Windows Update Issues

Before diving into the solutions, it helps to identify typical signs of update problems:

  • Updates stuck at 0%, 35%, or 100%
  • Update error codes like 0x800700020x800f081f, or 0x8024a105
  • "Windows Update Failed" or "There were problems installing updates"
  • PC crashes or slowdowns after an update
  • Restart loops or repeated update attempts

Step-by-Step Guide to Fix Windows Update Problems

 1. Restart Your PC and rerun updates

Sometimes (very rarely) a simple reboot clears temporary glitches in the update process.

Steps:

  • Click Start > Power > Restart
  • Try running Windows Update again

 2. Run the Windows Update Troubleshooter

Windows includes a built-in tool that can automatically detect and fix common update problems.

Steps:

  1. Open Settings > System > Troubleshoot > Other troubleshooters

  2. Find Windows Update and click Run

  3. Follow the prompts and apply any fixes it suggests

 3. Check Your Internet Connection

A slow or intermittent connection can prevent updates from downloading or installing.

Tips:

  • Ensure a stable connection
  • Avoid using mobile hotspots during large updates
  • Try a wired Ethernet connection if possible

4. Free Up Disk Space

Windows Update needs adequate space to download and install updates.

To free space:

  • Open Settings > System > Storage
  • Use Storage Sense or manually delete:

    • Temporary files
    • Old downloads
    • Unused programs

5. Manually Restart Windows Update Services

Windows Update relies on several background services. Restarting them can resolve stuck updates.

Steps:

  1. Press 

    Windows + R

    , type 

    services.msc

     and press Enter

  2. Find and restart the following:

    • Windows Update
    • Background Intelligent Transfer Service (BITS)
    • Cryptographic Services
  3. Right-click each > Restart

6. Clear the Windows Update Cache (SoftwareDistribution Folder)

Corrupted update files in the SoftwareDistribution folder can cause problems.

Steps:

  1. Press 

    Windows + R (key)

    type 

    Right-click > Run as Administrator

     

  2. Stop update services:

    net stop wuauserv
    net stop bits

     

  3. Delete the update cache:  

    Cmd line

    del /f /s /q %windir%\SoftwareDistribution\

  4. Restart services:  

    net start wuauserv net start bits

  5. Try updating again

7. Use the System File Checker (SFC) and DISM Tools

Corrupt system files can interfere with updates.

Steps:

  1. Open Command Prompt as Administrator

  2. Run SFC from cmd line:  

    sfc /scannow

  3. After it completes, run DISM:  

    DISM /Online /Cleanup-Image /RestoreHealth

These commands check for system corruption and repair it.

 8. Install Updates Manually via Microsoft Update Catalog

If a specific update keeps failing, download and install it manually.

Steps:

  1. Go to: https://www.catalog.update.microsoft.com/

  2. Search the KB number of the failed update

  3. Download the correct version for your system

  4. Run the installer

 9. Pause and Resume Updates

This can force Windows to reattempt updates cleanly.

Steps:

  1. Open Settings > Windows Update

  2. Click Pause updates for 1 week

  3. Restart your PC
  4. Go back and click Resume updates

10. Perform an In-Place Upgrade (Repair Install)

If nothing else works, a repair install reinstalls Windows while keeping your files and apps.

Steps:

  1. Download the Media Creation Tool from Microsoft

  2. Choose Upgrade this PC now

  3. Follow prompts and select Keep personal files and apps

This replaces system files and refreshes Windows Update components.

11. Use WuFix.bat script that refreshes services

wufix.bat

SC config trustedinstaller start=auto
net stop bits
net stop wuauserv
net stop msiserver
net stop cryptsvc
net stop appidsvc
Ren %Systemroot%\SoftwareDistribution SoftwareDistribution.old
Ren %Systemroot%\System32\catroot2 catroot2.old
regsvr32.exe /s atl.dll
regsvr32.exe /s urlmon.dll
regsvr32.exe /s mshtml.dll
netsh winsock reset
netsh winsock reset proxy
rundll32.exe pnpclean.dll,RunDLL_PnpClean /DRIVERS /MAXCLEAN
dism /Online /Cleanup-image /ScanHealth
dism /Online /Cleanup-image /CheckHealth
dism /Online /Cleanup-image /RestoreHealth
dism /Online /Cleanup-image /StartComponentCleanup
Sfc /ScanNow
net start bits
net start wuauserv
net start msiserver
net start cryptsvc
net start appidsvc

12. Contact Microsoft or other tech guru Help

If problems persist even after trying the above methods, consider:

  • Contacting Microsoft Support
  • Consulting with a local technician
  • Performing a clean install (as a last resort)

13. Few Final Tips for Smooth Windows Updates

  • Always back up important data before major updates
  • Keep drivers and antivirus software up to date
  • Avoid interrupting the PC during updates
  • Check for known issues on Microsoft’s support site before installing major feature updates

14. Advanced Commands and Additional Ways to Fix Windows Update Problems

These methods go deeper into system-level repairs and are ideal when the basic fixes fail.

14.1. Reset Windows Update Components Manually (Full Command Script)

Instead of just clearing the cache, reset all update-related services and components.

Steps:

Open Command Prompt as Administrator, and run these commands one at a time:

net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver

Rename update-related folders:

ren C:/\Windows/\SoftwareDistribution SoftwareDistribution.old ren C:/\Windows/\System32/\catroot2 catroot2.old

Restart the services:

net start wuauserv
net start cryptSvc
net start bits
net start msiserver

This fully resets the update components.

 14.2. Use PowerShell to Re-register Update DLLs

Sometimes DLLs (Dynamic Link Libraries) related to updates become unregistered.

Run this in PowerShell (Admin):

regsvr32 wuaueng.dll regsvr32 wups.dll regsvr32 wups2.dll regsvr32 wuwebv.dll regsvr32 wucltui.dll

 14.3. Use PowerShell to Force Update Scan and Install

Open PowerShell as Administrator, and run:

Install-Module PSWindowsUpdate -Force Import-Module PSWindowsUpdate Get-WindowsUpdate Install-WindowsUpdate -AcceptAll -AutoReboot

 You may be prompted to install NuGet or trust the repository—accept these prompts.

 14.4. Enable Update Services via Registry Editor (Caution)

If your update services are being disabled by group policy or a third-party app, you can reset the registry settings.

Steps:

  1. Press 

    Win + R

     → type 

    regedit

     → Enter

  2. Navigate to:

    HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU

  3. Delete values like NoAutoUpdateAUOptions, etc.

  4. Also check:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wuauserv

    • Ensure Start is set to 2 (automatic)

 Always back up your registry before editing!


 14.5. Check Group Policy Settings (Windows Pro or Enterprise)

Group Policy can block updates.

Steps:

  1. Press 

    Win + R

     → type 

    gpedit.msc

     → Enter

  2. Navigate to:

    Computer Configuration > Administrative Templates > Windows Components > Windows Update

  3. Check and disable any restrictive settings like:

    • No auto-restart with logged on users
    • Configure Automatic Updates
    • Do not connect to any Windows Update Internet locations

 14.6. Use the Windows Update Assistant

Download the latest Windows Update Assistant from the Microsoft website or Windows 11 equivalent.

  • This tool bypasses built-in update problems
  • It can force the latest feature update or build version

 14.7. Delete Windows Update Pending.xml File

Sometimes updates fail due to a corrupted 

Pending.xml

 file.

Steps:

  1. Open Command Prompt as Administrator

  2. Run:

    del %windir%\winsxs\pending.xml

 This is advanced; use only if you're stuck with a failed update loop.

 14.8. Use Event Viewer to Identify Update Errors

Event Viewer can show exactly which update or process is failing.

Steps:

  1. Press 

    Win + X

     → Event Viewer

  2. Navigate to:

    Windows Logs > System

  3. Filter by Error and Warning

  4. Look for sources like:

    • WindowsUpdateClient
    • CBS (Component-Based Servicing)
    • WUSA

Note any error codes or update KB numbers.

 14.9. Use Deployment Image Servicing and Management (DISM) from ISO

DISM can be more powerful when pointed to a known good source like an ISO image.

Steps:

  1. Mount a Windows ISO (right-click > Mount)

  2. Note the drive letter (e.g., D:)

  3. Run in CMD (Admin):

    cmd.exe

    DISM /Online /Cleanup-Image /RestoreHealth /Source:D:\Sources\install.wim /LimitAccess

Replace 

D:\

 with the correct drive.

 14.10. Revert Problematic Updates Using Recovery or Uninstall

If an update caused system problems:

Option A: Uninstall via Settings

  • Go to Settings > Windows Update > Update History > Uninstall updates

Option B: From Advanced Startup

  • Hold 

     

     while clicking Restart

  • Go to Troubleshoot > Advanced Options > Uninstall Updates 

15.How to install Windows 11 without losing files (Re-install windows with keeping All stored files)

15.1. Download and Use the Media Creation Tool:

  • Download the Media Creation Tool from Microsoft's website.

    a) Go to this website:
    www.microsoft.com/en-us/software-download/windows11

    b) Click Download Now.

    c) Open the file you downloaded.
    Double-click it.

    d) Accept everything.
    Click Accept and Install.

    e) Important:
    When it asks about keeping files, select:

    f) Keep personal files and apps

    Wait until it finishes.

    Your PC will restart many times.

    g) After install:
    Your files and programs will still be there.

  • Run the tool and choose to create installation media for another PC.
  • Select your language, architecture, and edition of Windows.
  • Choose to create either a USB flash drive or an ISO file.
  • Follow the on-screen instructions to complete the process. 

15.2 Perform a Clean Install or In-place Upgrade:

  • Clean Install: This will erase all your personal files, apps, and settings, so be sure to back up your data if you choose this option.
  • In-place Upgrade: This will keep your files, apps, and settings while reinstalling Windows. This is a good option if you want to try and preserve your existing setup.
  • To perform an in-place upgrade, boot from the installation media and choose the "Upgrade" option, according to Microsoft Support

1️⃣ Go to this website:
https://www.microsoft.com/en-us/software-download/windows11

2️⃣ Download “Installation Assistant.
Click Download Now.

3️⃣ Open the file you downloaded.
Double-click it.

4️⃣ Accept everything.
Click Accept and Install.

5️⃣ Important:
When it asks about keeping files, select:
✅ Keep personal files and apps

6️⃣ Wait until it finishes.

Your PC will restart many times.

It can take 1–2 hours.

After install, Your files and programs will still be there. But anyways just in case don't forget to create a full backup of everything important before you started.

Summary of Useful Commands

Purpose Command or Tool
Stop Update Services net stop wuauserv etc.
Delete Update Cache del %windir%\SoftwareDistribution\*.* /s /q
Run SFC sfc /scannow
Run DISM DISM /Online /Cleanup-Image /RestoreHealth
PowerShell Update Module Install-Module PSWindowsUpdate
Force Install Updates Install-WindowsUpdate -AcceptAll
Reset Update Components (Full) See above command sequence
Manual Update via Catalog

Conclusion

Windows Update problems can be frustrating, but they’re usually fixable with a methodical approach. From restarting services to clearing cache and running built-in tools, this guide covers all essential fixes. Staying updated ensures your PC remains secure, efficient, and compatible with the latest software.

Flush DNS on Mac OS X ,Windows and Linux from command line

Wednesday, January 8th, 2025

MAC OSX DNS Configuration | DNSFLEX

 

MAC OS X flush DNS cache


Open macOS /Mac OS X terminal application and type the following command under OS X version 10.5 and above:

# dscacheutil -flushcache

Mac OS X Tiger (v10.4) user, enter:

# lookupd -flushcache

macOS 11 Big Sur or 12 Monterey user, try:

# sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

 

macOS 10.11 El Capitan, 10.12 Sierra, 10.13 High Sierra, 10.14 Mojave, or 10.15 Catalina user try:

# sudo killall -HUP mDNSResponder

 

On Mac OS X version 10.6 and onwards to dump DNS cached records
 

$ dscacheutil -cachedump -entries

Display your DNS cached records on Windows
 
Implement Windows Server DNS - Training | Microsoft Learn

  DNS cached records are stored to offload the DNS from querying it all the time in order to resolve the questionable site domain IP.

To view most recent cached DNS records on Windows use cmd:
 

c:\Windows\> ipconfig /displaydns

 

Windows IP Configuration

    array805.prod.do.dsp.mp.microsoft.com
    —————————————-
    Record Name . . . . . : array805.prod.do.dsp.mp.microsoft.com
    Record Type . . . . . : 1
    Time To Live  . . . . : 1894
    Data Length . . . . . : 4
    Section . . . . . . . : Answer
    A (Host) Record . . . : 52.143.124.236


    telemetry-incoming.r53-2.services.mozilla.com
    —————————————-
    Record Name . . . . . : telemetry-incoming.r53-2.services.mozilla.com
    Record Type . . . . . : 1
    Time To Live  . . . . : 444
    Data Length . . . . . : 4
    Section . . . . . . . : Answer
    A (Host) Record . . . : 34.120.208.123


    tunnel.googlezip.net
    —————————————-
    Record Name . . . . . : tunnel.googlezip.net
    Record Type . . . . . : 1
    Time To Live  . . . . : 36756
    Data Length . . . . . : 4

Use up/down scroll array to see the cached record you need to view in the DNS cache.
 

Flush DNS Cache on Windows OS

 


Open the terminal (Start > Run > type cmd and press the [Enter] key) and type the following command to flush DNS on Win XP/2000/7/10 etc:

# ipconfig /flushdns

 

How to Flush DNS local cache queries on Linux

How to Flush DNS Cache on Linux | Linux How to Flush DNS Guide

 

If you’re using a Linux distro such as Ubuntu, here’s how to flush the DNS cache:

Open the terminal by pressing Ctrl + Alt + T or searching for “Terminal” in the Activities menu.
Run the following command:
If you are running Ubuntu 20.04 LTS Linux or older Linux distro using systemd-resolve, use: sudo systemd-resolve –flush-caches.
If you are running Ubuntu 22.04 LTS or newer, use: sudo resolvectl flush-caches.
Enter your administrator password when prompted, and the DNS cache will be flushed.

To check the change in the DNS record is real, you can check the DNS cache statistics:

# resolvectl statistics

On older Linux distributions where /etc/resolv.conf nameserver directives are used to set the DNS for the server, to flush the cache
only options is to either flush the server used cache or change the nameserver inside the file.

 

Check the DNS cache records on older Linux distros (requires NSCD daemon)

Assuming the nscd daemon is UP and running (if not you have to install it) to check the cached local DNS records on Linux do

# service nscd status 


Reviewing Your DNS Cache on modern Linux distros

The systemd-resolved daemon reacts to USR1 by writing its cache to the system logs. We can then use the journalctl command to filter out the DNS entries.

We'll use the killall command with USR1 To send the signal to the systemd-resolved daemon. Note that although we're using the killall command, the systemd-resolved daemon continues to run. This isn't a termination signal that we're sending.

$ sudo killall -USR1 systemd-resolved

Now we'll use the journalctl command with the -u (filter by systemd unit) option to extract the log entries that have been generated by systemd-resolved . We'll redirect that output into a text files called "dns.txt."

$ sudo journalctl -u systemd-resolved > dns.txt

Then check the DNS records

$ less dns.txt

 

Then find the cached mappings between domain names and IP addresses in.

How to Flush the dnsmasq Cache on Linux

The dnsmasq application provides a DNS cache and a DHCP server.

dnsmasq is popular among with users who want to run their own DNS server, especially on non-systemd installations.

Flushing the dnsmasq DNS cache is easy. We need to send the SIGHUP signal, which tells the dnsmasq daemon to effectively reinitialize. Doing so clears its DNS cache. To send the signal we use the killall command with the -HUP flag, and the name of the application.

$ sudo killall -HUP dnsmasq

yum search file in all installable RPM, find out which rpm package provides binary file or missing library dependency on CentOS / RHEL / Fedora

Friday, August 23rd, 2024

images/centos-rhel-yum-clean-var-cache-yum

Sometimes if you have a missing library or a file you know should be available via an rpm but you're not sure which RPM you have to install you have to look up for library or binary file amongs all available installable r[ms on Redhat Linux / CentOS / Fedora or other RPM based distro.

It is really annoying especially, if you try to install an rpm binary and the package does not install due to missing dependency library. Having a missing dependency package could happen, if you use some custom internal prepared repository that is mirroring from original rpm repositories and the RPM Repositories are situated behind a DMZ firewall network (such scenarios are common for corporations and IT companies).
 
Finding out which file is provided by which package on Debian / Ubuntu and other deb based linux distributions is easy and done via the

# apt-file search filename

Thus if you're a system administrator coming from a Debian GNU / Linux sysadmin realm into the wonderful world of redhats, you will want to have an alternative to apt-file tool. You will be happy to find out that that this tedious task is easily done in RPM based Linux and is integrated straight into yum package manager too.

The command to search which rpm package provides a file is:

# yum whatprovides 'nc'

[root@rhel-linux ~]# yum whatprovides nc
Loaded plugins: fastestmirror, versionlock
Loading mirror speeds from cached hostfile
2:nmap-ncat-6.40-19.el7.x86_64 : Nmap's Netcat replacement
Repo        : base
Matched from:
Provides    : nc

 

2:nmap-ncat-6.40-19.el7.x86_64 : Nmap's Netcat replacement
Repo        : @base
Matched from:
Provides    : nc

 

yum whatprovides search_file_name can be also invoked with its shortcut yum provides 'search_file_name'

[root@rhel-server ~]# yum provides '/bin/ls'
Loaded plugins: fastestmirror, versionlock
Loading mirror speeds from cached hostfile
coreutils-8.22-24.el7.x86_64 : A set of basic GNU tools commonly used in shell scripts
Repo        : base
Matched from:
Filename    : /bin/ls

coreutils-8.22-24.el7_9.2.x86_64 : A set of basic GNU tools commonly used in shell scripts
Repo        : updates
Matched from:
Filename    : /bin/ls

 Here is another example:

[root@rhel-server ~]# yum -q provides '*lesspipe.sh*'
less-458-9.el7.x86_64 : A text file browser similar to more, but better
Repo        : base
Matched from:
Filename    : /usr/bin/lesspipe.sh

source-highlight-3.1.6-6.el7.i686 : Produces a document with syntax highlighting
Repo        : base
Matched from:
Filename    : /usr/bin/src-hilite-lesspipe.sh

source-highlight-3.1.6-6.el7.x86_64 : Produces a document with syntax highlighting
Repo        : base
Matched from:
Filename    : /usr/bin/src-hilite-lesspipe.sh

spirv-tools-2019.1-4.el7.x86_64 : API and commands for processing SPIR-V modules
Repo        : epel
Matched from:
Filename    : /usr/bin/spirv-lesspipe.sh

You can search for any file and if the RPm repository is defined under /etc/yum/repos.d/* and enabled, yum whatprovides command should be able to find it and tell you which RPM package you have to install to have the file installed Redhat way.

  • You can list all enabled RPM repositories with cmd:
     

[root@rhel-server ~]# yum repolist enabled
Loaded plugins: fastestmirror, versionlock
Loading mirror speeds from cached hostfile
repo id                                                   repo name                                                                      status
3party                                                    Third party packages – x86_64                                                   2,631
base/7/x86_64                                             CentOS-7 – Base                                                                10,072
cr/7/x86_64                                               CentOS-7 – CR                                                                       0
epel/7/x86_64                                             EPEL packages for RedCent 7 – x86_64                                           13,791
extras/7/x86_64                                           CentOS-7 – Extras                                                                 526
updates/7/x86_64                                          CentOS-7 – Updates                                                              5,802
zabbix-6.0                                                Zabbix 6.0 repo                                                                   429
repolist: 33,251
 

  • To list disable RPM repositories:
     

# yum repolist disabled


To list all present available repositories that could be enabled and are set via the /etc/yum.repos.d/* configs

# yum repolist all

How to RIP audio CD and convert to MP3 format on Linux

Thursday, April 11th, 2024

I've been given a very tedious task to Copy music from Audio CD Drive to MP3 / MP4 file format and then copy the content to external Flash drive.
Doing so is pretty trivial, you just need to have a CD / DVD rom on your computer something that becomes rare nowadays and then you need to have installed a bunch of software, if you don't already have it as i've pointed in my previous article Howto craete Music Audio CD from MP3 files, create playable WAV format audio CD Albums from MP3s.

Creating a Audio CD from an MP3 collection is exactly the opposite to what is aim't now (to copy the content of a CD to a computer and prepare it for A Car MP3 player).

1. RIPing audio CDs to WAV and Conver to MP3 from terminal
 

On Linux there is  many ways to do it and many tools that can do it for your both graphical and command line.
But as I prefer command line to do stuff, in this article I'll mention the quickest and most elementary one which is done in 2 steps.

1. Use a tool to dump the CD Audio music to Tracks in WAV format
2. Convert the WAV to MP3 format

We'll need cdparanoia tool installed as well as ffmpeg.

If you don't have them installed do:

# apt-get install –yes cdparanoia dvd+rw-tools cdw cdrdao audiotools cdlabelgen dvd+rw-tools wodim ffmpeg lame normalize-audio libavcodec58

Next create the directory where you want to dump the .wav files.

# mkdir /home/hipo/audiorip/cd1
# cd /home/hipo/audiorip/cd1

Next assumng the Audio CD is plugged in the CD reader, dump its full content into track*.WAV files with cmd:

# paranoia -B

This will produce you the dumped songs into .wav files.

hipo@noah:~/audiorip/cd1$ ls -al *.wav
-rw-r–r– 1 root root  10278284 мар 25 22:49 track01.cdda.wav
-rw-r–r– 1 root root  21666668 мар 25 22:50 track02.cdda.wav
-rw-r–r– 1 root root  88334108 мар 25 22:53 track03.cdda.wav
-rw-r–r– 1 root root  53453948 мар 25 22:55 track04.cdda.wav
-rw-r–r– 1 root root 100846748 мар 25 22:58 track05.cdda.wav
-rw-r–r– 1 root root  41058908 мар 25 22:59 track06.cdda.wav
-rw-r–r– 1 root root 105952940 мар 25 23:02 track07.cdda.wav
-rw-r–r– 1 root root  50074124 мар 25 23:03 track08.cdda.wav
-rw-r–r– 1 root root  92555948 мар 25 23:06 track09.cdda.wav
-rw-r–r– 1 root root  61939964 мар 25 23:07 track10.cdda.wav
-rw-r–r– 1 root root   8521340 мар 25 23:07 track11.cdda.wav

Then you can use a simple for loop with ffmpeg command to conver the .wav files to .mp3s.

hipo@noah:~/audiorip/cd1$  for i in $( ls -1 *); do ffmpeg -i $i $i.wav.mp3; done
 

ffmpeg version 1.2.12 Copyright (c) 2000-2015 the FFmpeg developers
  built on Feb 12 2015 18:03:16 with gcc 4.7 (Debian 4.7.2-5)
  configuration: –prefix=/usr –extra-cflags='-g -O2 -fstack-protector –param=ssp-buffer-size=4 -Wformat -Werror=format-security ' –extra-ldflags='-Wl,-z,relro' –cc='ccache cc' –enable-shared –enable-libmp3lame –enable-gpl –enable-nonfree –enable-libvorbis –enable-pthreads –enable-libfaac –enable-libxvid –enable-postproc –enable-x11grab –enable-libgsm –enable-libtheora –enable-libopencore-amrnb –enable-libopencore-amrwb –enable-libx264 –enable-libspeex –enable-nonfree –disable-stripping –enable-libvpx –enable-libschroedinger –disable-encoder=libschroedinger –enable-version3 –enable-libopenjpeg –enable-librtmp –enable-avfilter –enable-libfreetype –enable-libvo-aacenc –disable-decoder=amrnb –enable-libvo-amrwbenc –enable-libaacplus –libdir=/usr/lib/x86_64-linux-gnu –disable-vda –enable-libbluray –enable-libcdio –enable-gnutls –enable-frei0r –enable-openssl –enable-libass –enable-libopus –enable-fontconfig –enable-libpulse –disable-mips32r2 –disable-mipsdspr1 –dis  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[wav @ 0x66c900] max_analyze_duration 5000000 reached at 5015510 microseconds
Guessed Channel Layout for  Input Stream #0.0 : stereo
Input #0, wav, from 'track01.cdda.wav':
  Duration: 00:00:23.19, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
Output #0, mp3, to 'track01.cdda.wav.wav.mp3':
  Metadata:
    TSSE            : Lavf54.63.104
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le -> libmp3lame)
Press [q] to stop, [?] for help
size=     363kB time=00:00:23.19 bitrate= 128.2kbits/s    
video:0kB audio:363kB subtitle:0 global headers:0kB muxing overhead 0.058402%
ffmpeg version 1.2.12 Copyright (c) 2000-2015 the FFmpeg developers
  built on Feb 12 2015 18:03:16 with gcc 4.7 (Debian 4.7.2-5)
  configuration: –prefix=/usr –extra-cflags='-g -O2 -fstack-protector –param=ssp-buffer-size=4 -Wformat -Werror=format-security ' –extra-ldflags='-Wl,-z,relro' –cc='ccache cc' –enable-shared –enable-libmp3lame –enable-gpl –enable-nonfree –enable-libvorbis –enable-pthreads –enable-libfaac –enable-libxvid –enable-postproc –enable-x11grab –enable-libgsm –enable-libtheora –enable-libopencore-amrnb –enable-libopencore-amrwb –enable-libx264 –enable-libspeex –enable-nonfree –disable-stripping –enable-libvpx –enable-libschroedinger –disable-encoder=libschroedinger –enable-version3 –enable-libopenjpeg –enable-librtmp –enable-avfilter –enable-libfreetype –enable-libvo-aacenc –disable-decoder=amrnb –enable-libvo-amrwbenc –enable-libaacplus –libdir=/usr/lib/x86_64-linux-gnu –disable-vda –enable-libbluray –enable-libcdio –enable-gnutls –enable-frei0r –enable-openssl –enable-libass –enable-libopus –enable-fontconfig –enable-libpulse –disable-mips32r2 –disable-mipsdspr1 –dis  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[mp3 @ 0x66c900] max_analyze_duration 5000000 reached at 5015510 microseconds
Input #0, mp3, from 'track01.cdda.wav.mp3':
  Metadata:
    encoder         : Lavf54.63.104
  Duration: 00:00:23.22, start: 0.000000, bitrate: 128 kb/s
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p, 128 kb/s
File 'track01.cdda.wav.mp3.wav.mp3' already exists. Overwrite ? [y/N] y
Output #0, mp3, to 'track01.cdda.wav.mp3.wav.mp3':
  Metadata:
    TSSE            : Lavf54.63.104
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (mp3 -> libmp3lame)
Press [q] to stop, [?] for help
Trying to remove 1152 samples, but the queue is emptys    
size=     363kB time=00:00:23.24 bitrate= 128.1kbits/s    
video:0kB audio:363kB subtitle:0 global headers:0kB muxing overhead 0.058336%
ffmpeg version 1.2.12 Copyright (c) 2000-2015 the FFmpeg developers
  built on Feb 12 2015 18:03:16 with gcc 4.7 (Debian 4.7.2-5)
  configuration: –prefix=/usr –extra-cflags='-g -O2 -fstack-protector –param=ssp-buffer-size=4 -Wformat -Werror=format-security ' –extra-ldflags='-Wl,-z,relro' –cc='ccache cc' –enable-shared –enable-libmp3lame –enable-gpl –enable-nonfree –enable-libvorbis –enable-pthreads –enable-libfaac –enable-libxvid –enable-postproc –enable-x11grab –enable-libgsm –enable-libtheora –enable-libopencore-amrnb –enable-libopencore-amrwb –enable-libx264 –enable-libspeex –enable-nonfree –disable-stripping –enable-libvpx –enable-libschroedinger –disable-encoder=libschroedinger –enable-version3 –enable-libopenjpeg –enable-librtmp –enable-avfilter –enable-libfreetype –enable-libvo-aacenc –disable-decoder=amrnb –enable-libvo-amrwbenc –enable-libaacplus –libdir=/usr/lib/x86_64-linux-gnu –disable-vda –enable-libbluray –enable-libcdio –enable-gnutls –enable-frei0r –enable-openssl –enable-libass –enable-libopus –enable-fontconfig –enable-libpulse –disable-mips32r2 –disable-mipsdspr1 –dis  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[mp3 @ 0x66c900] max_analyze_duration 5000000 reached at 5015510 microseconds
Input #0, mp3, from 'track01.cdda.wav.mp3.wav.mp3':
  Metadata:
    encoder         : Lavf54.63.104
  Duration: 00:00:23.25, start: 0.000000, bitrate: 128 kb/s
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p, 128 kb/s
Output #0, mp3, to 'track01.cdda.wav.mp3.wav.mp3.wav.mp3':
  Metadata:
    TSSE            : Lavf54.63.104
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (mp3 -> libmp3lame)
Press [q] to stop, [?] for help
Trying to remove 1152 samples, but the queue is emptys    
size=     364kB time=00:00:23.27 bitrate= 128.1kbits/s    
video:0kB audio:364kB subtitle:0 global headers:0kB muxing overhead 0.058271%
ffmpeg version 1.2.12 Copyright (c) 2000-2015 the FFmpeg developers
  built on Feb 12 2015 18:03:16 with gcc 4.7 (Debian 4.7.2-5)
  configuration: –prefix=/usr –extra-cflags='-g -O2 -fstack-protector –param=ssp-buffer-size=4 -Wformat -Werror=format-security ' –extra-ldflags='-Wl,-z,relro' –cc='ccache cc' –enable-shared –enable-libmp3lame –enable-gpl –enable-nonfree –enable-libvorbis –enable-pthreads –enable-libfaac –enable-libxvid –enable-postproc –enable-x11grab –enable-libgsm –enable-libtheora –enable-libopencore-amrnb –enable-libopencore-amrwb –enable-libx264 –enable-libspeex –enable-nonfree –disable-stripping –enable-libvpx –enable-libschroedinger –disable-encoder=libschroedinger –enable-version3 –enable-libopenjpeg –enable-librtmp –enable-avfilter –enable-libfreetype –enable-libvo-aacenc –disable-decoder=amrnb –enable-libvo-amrwbenc –enable-libaacplus –libdir=/usr/lib/x86_64-linux-gnu –disable-vda –enable-libbluray –enable-libcdio –enable-gnutls –enable-frei0r –enable-openssl –enable-libass –enable-libopus –enable-fontconfig –enable-libpulse –disable-mips32r2 –disable-mipsdspr1 –dis  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[wav @ 0x66c900] max_analyze_duration 5000000 reached at 5015510 microseconds
Guessed Channel Layout for  Input Stream #0.0 : stereo
Input #0, wav, from 'track02.cdda.wav':
  Duration: 00:02:21.28, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
Output #0, mp3, to 'track02.cdda.wav.wav.mp3':
  Metadata:
    TSSE            : Lavf54.63.104
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le -> libmp3lame)
Press [q] to stop, [?] for help


Finally remove the old unneded .wav files and enjoy the mp3s with vlc / mplayer / mpg123 or whatever player you like.

hipo@noah:~/audiorip/cd1$  rm -f *.wav


Now mount the flash drive and copy th files into it.

# mkdir /media/usb-drive
# mount /dev/sdc1 /media/usb-drive/
# mkdir -p /media/usb-drive/cd1
# fdisk -l |grep -i sdc1

/dev/sdc1 on /media/usb-drive type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=utf8,shortname=mixed,errors=remount-ro

# cp -rpf ~/audiorip/cd1*.mp3 /mnt/usb-drive/cd1
# umount /dev/sdc1


2. RIPping audio CD on Linux with rip-audio-cds-linux.sh  script
 

#!/bin/bash
# A simple shell script to rip audio cd and create mp3 using lame
# and cdparanoia utilities.
# —————————————————————————-
# Written by Vivek Gite <http://www.cyberciti.biz/>
# (c) 2006 nixCraft under GNU GPL v2.0+
# —————————————————————————-
read -p "Starting in 5 seconds ( to abort press CTRL + C ) " -t 5
cdparanoia -B
for i in *.wav
do
    lame –vbr-new -b 360 "$i" "${i%%.cdda.wav}.mp3"
    rm -f "$i"
done


If you need to automate the task of dumping the audio CDs to WAV and convert them to MP3s you can do it via a small shell script like the one provided by cyberciti.biz that uses paranoia and lame commands in a shell script loop. Script rip-audio-cds-linux.sh is here

3. Dump Audio CD to MP3 with Graphical program ( ripperx ) 

By default most modern Linux distributions including the Debian GNU / Linux based ones has the ripperx in the default repositories, as well as the tool is downloadable and compilable from source from sourceforge.net 

ripping-audio-cds-linux-graphical-program-ripperx-tool

# apt-cache show ripperx|grep -i descript -A3 -B3
Architecture: amd64
Depends: cdparanoia, vorbis-tools (>= 1.0beta3), libatk1.0-0 (>= 1.12.4), libc6 (>= 2.14), libcairo2 (>= 1.2.4), libfontconfig1 (>= 2.12.6), libfreetype6 (>= 2.2.1), libgcc1 (>= 1:3.0), libgdk-pixbuf2.0-0 (>= 2.22.0), libglib2.0-0 (>= 2.16.0), libgtk2.0-0 (>= 2.8.0), libpango-1.0-0 (>= 1.14.0), libpangocairo-1.0-0 (>= 1.14.0), libpangoft2-1.0-0 (>= 1.14.0), libstdc++6 (>= 5.2), libtag1v5 (>= 1.9.1-2.2~)
Suggests: sox, cdtool, mpg321, flac, toolame
Description-en: GTK-based audio CD ripper/encoder
 ripperX is a graphical interface for ripping CD audio tracks (using
 cdparanoia) and then encoding them into the Ogg, FLAC, or MP2/3
 formats using the vorbis tools, FLAC, toolame or other available
 MP3 encoders.
 .
 It includes support for CDDB lookups and ID3v2 tags.
Description-md5: cdeabf4ef72c33d57aecc4b4e2fd5952
Homepage: http://sourceforge.net/projects/ripperx/
Tag: hardware::storage, hardware::storage:cd, interface::graphical,
 interface::x11, role::program, scope::application, uitoolkit::gtk,

# apt install –yes ripperx


https://www.pc-freak.net/images/ripperx-linux-gui-rip-audio-cds-tool

That's all folks.
Enjoy !

How to count number of ESTABLISHED state TCP connections to a Windows server

Wednesday, March 13th, 2024

count-netstat-established-connections-on-windows-server-howto-windows-logo-debug-network-issues-windows

Even if you have the background of a Linux system administrator, sooner or later you will have have to deal with some Windows hosts, thus i'll blog in this article shortly on how the established TCP if it happens you will have to administarte a Windows hosts or help a windows sysadmin noobie 🙂

In Linux it is pretty easy to check the number of established conenctions, because of the wonderful command wc (word count). with a simple command like:
 

$ netstat -etna |wc -l


Then you will get the number of active TCP connections to the machine and based on that you can get an idea on how busy the server is.

But what if you have to deal with lets say a Microsoft Windows 2012 /2019 / 2020 or 2022 Server, assuming you logged in as Administrator and you see the machine is quite loaded and runs multiple Native Windows Administrator common services such as IIS / Active directory Failover Clustering, Proxy server etc.
How can you identify the established number of connections via a simple command in cmd.exe?

1.Count ESTABLISHED TCP connections from Windows Command Line

Here is the answer, simply use netstat native windows command and combine it with find, like that and use the /i (ignores the case of characters when searching the string) /c (count lines containing the string) options

C:\Windows\system32>netstat -p TCP -n|  find /i "ESTABLISHED" /c
1268

Voila, here are number of established connections, only 1268 that is relatively low.
However if you manage Windows servers, and you get some kind of hang ups as part of the monitoring, it is a good idea to setup a script based on this simple command for at least Windows Task Scheduler (the equivallent of Linux's crond service) to log for Peaks in Established connections to see whether Server crashes are not related to High Rise in established connections.
Even better if company uses Zabbix / Nagios, OpenNMS or other  old legacy monitoring stuff like Joschyd even as of today 2024 used in some big of the TOP IT companies such as SAP (they were still using it about 4 years ago for their SAP HANA Cloud), you can set the script to run and do a Monitoring template or Alerting rules to draw you graphs and Trigger Alerts if your connections hits a peak, then you at least might know your Windows server is under a "Hackers" Denial of Service attack or there is something happening on the network, like Cisco Network Infrastructure Switch flappings or whatever.

Perhaps an example script you can use if you decide to implement the little nestat established connection checks Monitoring in Zabbix is the one i've writen about in the previous article "Calculate established connection from IP address with shell script and log to zabbix graphic".

2. Few Useful netstat options for the Windows system admin
 

C:\Windows\System32> netstat -bona


netstat-useful-arguments-for-the-windows-system-administrator

Cmd.exe will lists executable files, local and external IP addresses and ports, and the state in list form. You immediately see which programs have created connections or are listening so that you can find offenders quickly.

b – displays the executable involved in  creating the connection.
o – displays the owning process ID.
n – displays address and port numbers.
a – displays all connections and listening ports.

As you can see in the screenshot, by using netstat -bona you get which process has binded to which local address and the Process ID PID of it, that is pretty useful in debugging stuff.

3. Use a Third Party GUI tool to debug more interactively connection issues

If you need to keep an eye in interactive mode, sometimes if there are issues CurrPorts tool can be of a great help

currports-windows-network-connections-diagnosis-cports

CurrPorts Tool own Description

CurrPorts is network monitoring software that displays the list of all currently opened TCP/IP and UDP ports on your local computer. For each port in the list, information about the process that opened the port is also displayed, including the process name, full path of the process, version information of the process (product name, file description, and so on), the time that the process was created, and the user that created it.
In addition, CurrPorts allows you to close unwanted TCP connections, kill the process that opened the ports, and save the TCP/UDP ports information to HTML file , XML file, or to tab-delimited text file.
CurrPorts also automatically mark with pink color suspicious TCP/UDP ports owned by unidentified applications (Applications without version information and icons).

Sum it up

What we learned is how to calculate number of established TCP connections from command line, useful for scripting, how you can use netstat to display the process ID and Process name that relates to a used Local / Remote TCP connections, and how eventually you can use this to connect it to some monitoring tool to periodically report High Peaks with TCP established connections (usually an indicator of servere system issues).
 

How to disable Windows pagefile.sys and hiberfil.sys to temporary or permamently save disk space if space is critically low

Monday, March 28th, 2022

howto-pagefile-hiberfil.sys-remove-reduce-increase-increase-size-windows-logo

Sometimes you have to work with Windows 7 / 8 / 10 PCs  etc. that has a very small partition C:\
drive or othertimes due to whatever the disk got filled up with time and has only few megabytes left
and this totally broke up the windows performance as Windows OS becomes terribly sluggish and even
simple things as opening Internet Browser (Chrome / Firefox / Opera ) or Windows Explorer stones the PC performance.

You might of course try to use something like Spacesniffer tool (a great tool to find lost data space on PC s short description on it is found in my previous article how to
delete temporary Internet Files and Folders to to speed up and free disk space
 ) or use CCleaner to clean up a bit the pc.
Sometimes this is not enough though or it is not possible to do at all the main
partition disk C:\ is anyhow too much low (only 30-50MB are available on HDD) or the Physical or Virtual Machine containing the OS is filled with important data
and you couldn't risk to remove anything including Internet Temporary files, browsing cookies … whatever.

Lets say you are the fate chosen guy as sysadmin to face this uneasy situation and have no easy
way to add disk space from another present free space partition or could not add a new SATA hard drive
SSD drive, what should you do?
 

The solution wipe off pagefile.sys and hiberfil.sys

Usually every Windows installation has a pagefile.sys and hiberfil.sys.

  • pagefile.sys – is the default file that is used as a swap file, immediately once the machine runs out of memory. For Unix / Linux users better understanding pagefile.sys is the equivallent of Linux's swap partition. Of course as the pagefile is in a file and not in separate partition the swapping in Windows is perhaps generally worse than in Linux.
  • hiberfil.sys – is used to store data from the machine on machine Hibernation (for those who use the feature)


Pagefile.sys which depending on the configured RAM memory on the OS could takes up up to 5 – 8 GB, there hanging around doing nothing but just occupying space. Thus a temporary workaround that could free you some space even though it will degrade performance and on servers and production machines this is not a good solution on just user machines, where you temporary need to free space any other important task you can free up space
by seriously reducing the preconfigured default size of pagefile.sys (which usually is 1.5 times the active memory on the OS – hence if you have 4GB you would have a 6Gigabytes of pagefile.sys).

Other possibility especially on laptop and movable devices running Win OS is to disable hiberfil.sys, read below how this is done.


The temporary solution here is to simply free space by either reducing the pagefile.sys or completely disabling it


1. Disable pagefile.sys on Windows XP, Windows 7 / 8 / 10 / 11


The GUI interface to disable pagefile across all NT based Windows OS-es is quite similar, the only difference is newer versions of Windows has slightly more options.


1.1 Disable pagefile on Windows XP


Quickest way is to find pagefile.sys settings from GUI menus

1. Computer (My Computer) – right click mouse
2. Properties (System Preperties will appear)
3. Advanced (tab) 
4. Settings
5. Advanced (tab)
6. Change button

windows-xp-pagefile-disable-screenshot

1.2 Disable pagefile on Windows 7

 

advanced-system-settings-control-panel-system-and-security-screenshot

windows-system-properties-screenshot-properties-advanced-change-Virtual-memory-pagefile-screenshot

system-properties-performance-options
 

Once applied you'll be required to reboot the PC

How-to-turn-off-Virtual-Memory-Paging_File-in-Windows-7-restart

 

1.3 Disable Increase / Decrease pagefile.sys on Windows 10 / Win 11
 

open-system-properties-advanced-win10

win10-performance-options-menu-screenshot

configure-virtual-memory-win-10-screenshot


1.4 Make Windows clear pagefile.sys on shutdown

On home PCs it might be useful thing to clear up ( nullify) pagefile.sys on shutdown, that could save you some disk space on every reboot, until file continuously grows to its configured Maximum.

Run

regedit

Modify registry key at location

 

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management

windows-clean-up-pagefile-sys-file-on-shutdown-or-reboot-registry-editor-value-screenshot

You can apply the value also via a registry file you can get the Enable Clearpagefile at shutdown here .reg.
 

2. Manipulating pagefile.sys size and file delete from command line with wmic tool 

For scripting purposes you might want to use the wmic pagefile which can do increase / decrase or delete the file without GUI, that is very helpful if you have to admin a Windows Domain (Active Directory)
 

[hipo.WINDOWS-PC] ➤ wmic pagefile /?

PAGEFILE – Virtual memory file swapping management.

HINT: BNF for Alias usage.
(<alias> [WMIObject] | [] | [] ) [].

USAGE:

PAGEFILE ASSOC []
PAGEFILE CREATE <assign list>
PAGEFILE DELETE
PAGEFILE GET [] []
PAGEFILE LIST [] []

 

[hipo.WINDOWS-PC] ➤ wmic pagefile
AllocatedBaseSize  Caption          CurrentUsage  Description      InstallDate                Name             PeakUsage  Status  TempPageFile
4709               C:\pagefile.sys  499           C:\pagefile.sys  20200912061902.938000+180  C:\pagefile.sys  525                FALSE

 

[hipo.WINDOWS-PC] ➤ wmic pagefile list /format:list

AllocatedBaseSize=4709
CurrentUsage=499
Description=C:\pagefile.sys
InstallDate=20200912061902.938000+180
Name=C:\pagefile.sys
PeakUsage=525
Status=
TempPageFile=FALSE

wmic-pagefile-command-line-tool-for-windows-default-output-screenshot

 

  • To change the Initial Size or Maximum Size of Pagefile use:
     

➤ wmic pagefileset where name="C:\\pagefile.sys" set InitialSize=2048,MaximumSize=2048

  • To move the pagefile / change location of pagefile to less occupied disk drive partition (i.e. D:\ drive)

     

     

    Sometimes you might have multiple drives on the PC and some of them might be having multitudes of gigabytes while main drive C:\ could be fully occupied due to initial install bad drive organization, in that case a good work arount to save you space so you can work normally with the server is just to temporary or permanently move pagefile to another drive.

wmic pagefileset where name="D:\\pagefile.sys" set InitialSize=2048,MaximumSize=2048


!! CONSIDER !!! 

That if you have the option to move the pagefile.sys for best performance it is advicable to place the file inside another physical disk, preferrably a Solid State Drive one, SATA disks are too slow and reduced Input / Output disk operations will lead to degraded performance, if there is lack of memory (i.e. pagefile.sys is actively open read and wrote in).
 

  • To delete pagefile.sys 
     

➤ wmic pagefileset where name="C:\\pagefile.sys" delete

 

If for some reason you prefer to not use wmic but simple del command you can delete pagefile.sys also by:

Removing file default "Hidden" and "system" file attributes – set for security reasons as the file is a system file usually not touched by user. This will save you from "permission denied" errors:
 

➤ attrib -s -h %systemdrive%\pagefile.sys


Delete the file:
 

➤ del /a /q %systemdrive%\pagefile.sys


3. Disable hibernation on Windows 7 / 8 and Win 10 / 11

Disabling hibernation file hiberfil.sys can also free up some space, especially if the hibernation has been actively used before and the file is written with data. Of course, that is more common on notebooks.
Windows hibernation has significantly improved over time though i didn't have very pleasant experience in the past and I prefer to disable it just in case.
 

3.1 Disable Windows 7 / 8 / 10 / 11 hibernation from GUI 

Disable it through:

Control Panel -> All Control Panel Items -> Power Options -> Edit Plan Settings -> Change advanced power settings


 like shown in below screenshot:

Windqows-power-options-Advanced-settings-Allow-Hybrid-sleep-option-menu-screenshot

 

3.2 Disable Windows 7 / 8 / 10 / 11 hibernation from command line

Disable hibernation Is done in the same way through the powercfg.exe command, to disable it
if you're cut of disk space and you want to save space from it:

run as Administrator in Command Line Windows (cmd.exe)
 

powercfg.exe /hibernate off

If you later need to switch on hibernation
 

powercfg.exe /hibernate on


disable-hiberfile-windows-screenshot

3.3 Disable Windows hibernation on legacy Windows XP

On XP to disable hibernation open

1. Power Options Properties
2. Select Hibernate
3. Select Enable Hibernation to clear the checkbox and disable Hibernation mode. 
4. Select OK to apply the change.

Close the Power Options Properties box. 

enable-disable-hibernate-windows-xp-menu-screenshot

To sum it up

We have learned some basics on Windows swapping and hibernation and i've tried to give some insight on how thiese files if misconfigured could lead to degraded Win OS performance. In any case using SSD as of 2022 to store both files is a best practice for machines that has plenty of memory always try to completely disable / remove the files. It was shown how  to manage pagefile.sys and hiberfil.sys across Windows Operating Systems different versions both from GUI and via command line as well as how you can configure pagefile.sys to be cleared up on pc reboot.
 

Fix Out of inodes on Postfix Linux Mail Cluster. How to clean up filesystem running out of Inodes, Filesystem inodes on partition is 100% full

Wednesday, August 25th, 2021

Inode_Entry_inode-table-content

Recently we have faced a strange issue with with one of our Clustered Postfix Mail servers (the cluster is with 2 nodes that each has configured Postfix daemon mail servers (running on an OpenVZ virtualized environment).
A heartbeat that checks liveability of clusters and switches nodes in case of one of the two gets broken due to some reason), pretty much a standard SMTP cluster.

So far so good but since the cluster is a kind of abondoned and is pretty much legacy nowadays and used just for some Monitoring emails from different scripts and systems on servers, it was not really checked thoroughfully for years and logically out of sudden the alarming email content sent via the cluster stopped working.

The normal sysadmin job here  was to analyze what is going on with the cluster and fix it ASAP. After some very basic analyzing we catched the problem is caused by a  "inodes full" (100% of available inodes were occupied) problem, e.g. file system run out of inodes on both machines perhaps due to a pengine heartbeat process  bug  leading to producing a high number of .bz2 pengine recovery archive files stored in /var/lib/pengine>

Below are the few steps taken to analyze and fix the problem.
 

1. Finding out about the the system run out of inodes problem


After logging on to system and not finding something immediately is wrong with inodes, all I can see from crm_mon is cluster was broken.
A plenty of emails were left inside the postfix mail queue visible with a standard command

[root@smtp1: ~ ]# postqueue -p

It took me a while to find ot the problem is with inodes because a simple df -h  was showing systems have enough space but still cluster quorum was not complete.
A bit of further investigation led me to a  simple df -i reporting the number of inodes on the local filesystems on both our SMTP1 and SMTP2 got all occupied.

[root@smtp1: ~ ]# df -i
Filesystem            Inodes   IUsed   IFree IUse% Mounted on
/dev/simfs            500000   500000  0   100% /
none                   65536      61   65475    1% /dev

As you can see the number of inodes on the Virual Machine are unfortunately depleted

Next step was to check directories occupying most inodes, as this is the place from where files could be temporary moved to a remote server filesystem or moved to another partition with space on a server locally attached drives.
Below command gives an ordered list with directories locally under the mail root filesystem / and its respective occupied number files / inodes,
the more files under a directory the more inodes are being occupied by the files on the filesystem.

 

run-out-if-inodes-what-is-inode-find-out-which-filesystem-or-directory-eating-up-all-your-system-inodes-linux_inode_diagram.gif
1.1 Getting which directory consumes most of the inodes on the systems

 

[root@smtp1: ~ ]# { find / -xdev -printf '%h\n' | sort | uniq -c | sort -k 1 -n; } 2>/dev/null
….
…..

…….
    586 /usr/lib64/python2.4
    664 /usr/lib64
    671 /usr/share/man/man8
    860 /usr/bin
   1006 /usr/share/man/man1
   1124 /usr/share/man/man3p
   1246 /var/lib/Pegasus/prev_repository_2009-03-10-1236698426.308128000.rpmsave/root#cimv2/classes
   1246 /var/lib/Pegasus/prev_repository_2009-05-18-1242636104.524113000.rpmsave/root#cimv2/classes
   1246 /var/lib/Pegasus/prev_repository_2009-11-06-1257494054.380244000.rpmsave/root#cimv2/classes
   1246 /var/lib/Pegasus/prev_repository_2010-08-04-1280907760.750543000.rpmsave/root#cimv2/classes
   1381 /var/lib/Pegasus/prev_repository_2010-11-15-1289811714.398469000.rpmsave/root#cimv2/classes
   1381 /var/lib/Pegasus/prev_repository_2012-03-19-1332151633.572875000.rpmsave/root#cimv2/classes
   1398 /var/lib/Pegasus/repository/root#cimv2/classes
   1696 /usr/share/man/man3
   400816 /var/lib/pengine

Note, the above command orders the files from bottom to top order and obviosuly the bottleneck directory that is over-eating Filesystem inodes with an exceeding amount of files is
/var/lib/pengine
 

2. Backup old multitude of files just in case of something goes wrong with the cluster after some files are wiped out


The next logical step of course is to check what is going on inside /var/lib/pengine just to find a very ,very large amount of pe-input-*NUMBER*.bz2 files were suddenly produced.

 

[root@smtp1: ~ ]# ls -1 pe-input*.bz2 | wc -l
 400816


The files are produced by the pengine process which is one of the processes that is controlling the heartbeat cluster state, presumably it is done by running process:

[root@smtp1: ~ ]# ps -ef|grep -i pengine
24        5649  5521  0 Aug10 ?        00:00:26 /usr/lib64/heartbeat/pengine


Hence in order to fix the issue, to prevent some inconsistencies in the cluster due to the file deletion,  copied the whole directory to another mounted parition (you can mount it remotely with sshfs for example) or use a local one if you have one:

[root@smtp1: ~ ]# cp -rpf /var/lib/pengine /mnt/attached_storage


and proceeded to clean up some old multitde of files that are older than 2 years of times (720 days):


3. Clean  up /var/lib/pengine files that are older than two years with short loop and find command

 


First I made a list with all the files to be removed in external text file and quickly reviewed it by lessing it like so

[root@smtp1: ~ ]#  cd /var/lib/pengine
[root@smtp1: ~ ]# find . -type f -mtime +720|grep -v pe-error.last | grep -v pe-input.last |grep -v pe-warn.last -fprint /home/myuser/pengine_older_than_720days.txt
[root@smtp1: ~ ]# less /home/myuser/pengine_older_than_720days.txt


Once reviewing commands I've used below command to delete the files you can run below command do delete all older than 2 years that are different from pe-error.last / pe-input.last / pre-warn.last which might be needed for proper cluster operation.

[root@smtp1: ~ ]#  for i in $(find . -type f -mtime +720 -exec echo '{}' \;|grep -v pe-error.last | grep -v pe-input.last |grep -v pe-warn.last); do echo $i; done


Another approach to the situation is to simply review all the files inside /var/lib/pengine and delete files based on year of creation, for example to delete all files in /var/lib/pengine from 2010, you can run something like:
 

[root@smtp1: ~ ]# for i in $(ls -al|grep -i ' 2010 ' | awk '{ print $9 }' |grep -v 'pe-warn.last'); do rm -f $i; done


4. Monitor real time inodes freeing

While doing the clerance of old unnecessery pengine heartbeat archives you can open another ssh console to the server and view how the inodes gets freed up with a command like:

 

# check if inodes is not being rapidly decreased

[root@csmtp1: ~ ]# watch 'df -i'


5. Restart basic Linux services producing pid files and logs etc. to make then workable (some services might not be notified the inodes on the Hard drive are freed up)

Because the hard drive on the system was full some services started to misbehaving and /var/log logging was impacted so I had to also restart them in our case this is the heartbeat itself
that  checks clusters nodes availability as well as the logging daemon service rsyslog

 

# restart rsyslog and heartbeat services
[root@csmtp1: ~ ]# /etc/init.d/heartbeat restart
[root@csmtp1: ~ ]# /etc/init.d/rsyslog restart

The systems had been a data integrity legacy service samhain so I had to restart this service as well to reforce the /var/log/samhain log file to again continusly start writting data to HDD.

# Restart samhain service init script 
[root@csmtp1: ~ ]# /etc/init.d/samhain restart


6. Check up enough inodes are freed up with df

[root@smtp1 log]# df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/simfs 500000 410531 19469 91% /
none 65536 61 65475 1% /dev


I had to repeat the same process on the second Postfix cluster node smtp2, and after all the steps like below check the status of smtp2 node and the postfix queue, following same procedure made the second smtp2 cluster member as expected 🙂

 

7. Check the cluster node quorum is complete, e.g. postfix cluster is operating normally

 

# Test if email cluster is ok with pacemaker resource cluster manager – lt-crm_mon
 

[root@csmtp1: ~ ]# crm_mon -1
============
Last updated: Tue Aug 10 18:10:48 2021
Stack: Heartbeat
Current DC: smtp2.fqdn.com (bfb3d029-89a8-41f6-a9f0-52d377cacd83) – partition with quorum
Version: 1.0.12-unknown
2 Nodes configured, unknown expected votes
4 Resources configured.
============

Online: [ smtp2.fqdn.com smtp1.fqdn.com ]

failover-ip (ocf::heartbeat:IPaddr2): Started csmtp1.ikossvan.de
Clone Set: postfix_clone
Started: [ smtp2.fqdn.com smtp1fqdn.com ]
Clone Set: pingd_clone
Started: [ smtp2.fqdn.com smtp1.fqdn.com ]
Clone Set: mailto_clone
Started: [ smtp2.fqdn.com smtp1.fqdn.com ]

 

8.  Force resend a few hundred thousands of emails left in the email queue


After some inodes gets freed up due to the file deletion, i've reforced a couple of times the queued mail servers to be immediately resent to remote mail destinations with cmd:

 

# force emails in queue to be resend with postfix

[root@smtp1: ~ ]# sendmail -q


– It was useful to watch in real time how the queued emails are quickly decreased (queued mails are successfully sent to destination addresses) with:

 

# Monitor  the decereasing size of the email queue
[root@smtp1: ~ ]# watch 'postqueue -p|grep -i '@'|wc -l'

Linux: Howto Fix “N: Repository ‘http://deb.debian.org/debian buster InRelease’ changed its ‘Version’ value from ‘10.9’ to ‘10.10’” error to resolve apt-get release update issue

Friday, August 13th, 2021

Linux's surprises and disorganization is continuously growing day by day and I start to realize it is becoming mostly impossible to support easily this piece of hackware bundled together.
Usually so far during the last 5 – 7 years, I rarely had any general issues with using:

 apt-get update && apt-get upgrade && apt-get dist-upgrade 

to raise a server's working stable Debian Linux version packages e.g. version X.Y to verzion X.Z (for example up the release from Debian Jessie from 8.1 to 8.2). 

Today I just tried to follow this well known and established procedure that, of course nowdays is better to be done with the newer "apt" command instead with the legacy "apt-get"
And the set of 

 

# apt-get update && apt-get upgrade && apt-get dist-upgrade

 

has triggered below shitty error:
 

root@zabbix:~# apt-get update && apt-get upgrade
Get:1 http://security.debian.org buster/updates InRelease [65.4 kB]
Get:2 http://deb.debian.org/debian buster InRelease [122 kB]
Get:3 http://security.debian.org buster/updates/non-free Sources [688 B]
Get:4 http://repo.zabbix.com/zabbix/5.0/debian buster InRelease [7096 B]
Get:5 http://security.debian.org buster/updates/main Sources [198 kB]
Get:6 http://security.debian.org buster/updates/main amd64 Packages [300 kB]
Get:7 http://security.debian.org buster/updates/main Translation-en [157 kB]
Get:8 http://security.debian.org buster/updates/non-free amd64 Packages [556 B]
Get:9 http://deb.debian.org/debian buster/main Sources [7836 kB]
Get:10 http://repo.zabbix.com/zabbix/5.0/debian buster/main Sources [1192 B]
Get:11 http://repo.zabbix.com/zabbix/5.0/debian buster/main amd64 Packages [4785 B]
Get:12 http://deb.debian.org/debian buster/non-free Sources [85.7 kB]
Get:13 http://deb.debian.org/debian buster/contrib Sources [42.5 kB]
Get:14 http://deb.debian.org/debian buster/main amd64 Packages [7907 kB]
Get:15 http://deb.debian.org/debian buster/main Translation-en [5968 kB]
Get:16 http://deb.debian.org/debian buster/main amd64 Contents (deb) [37.3 MB]
Get:17 http://deb.debian.org/debian buster/contrib amd64 Packages [50.1 kB]
Get:18 http://deb.debian.org/debian buster/non-free amd64 Packages [87.7 kB]
Get:19 http://deb.debian.org/debian buster/non-free Translation-en [88.9 kB]
Get:20 http://deb.debian.org/debian buster/non-free amd64 Contents (deb) [861 kB]
Fetched 61.1 MB in 22s (2774 kB/s)
Reading package lists… Done
N: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Version' value from '10.9' to '10.10'


As I used to realize nowdays, as Linux started originally as 'Hackers' operating system, its legacy is just one big hack and everything from simple maintenance up to the higher and more sophisticated things requires a workaround 'hack''.

 

This time the hack to resolve error:
 

N: Repository 'http://deb.debian.org/debian buster InRelease' changed its 'Version' value from '10.9' to '10.10'


is up to running cmd:
 

debian-server:~# apt-get update –allow-releaseinfo-change
Поп:1 http://ftp.de.debian.org/debian buster-backports InRelease
Поп:2 http://ftp.debian.org/debian stable InRelease
Поп:3 http://security.debian.org stable/updates InRelease
Изт:5 https://packages.sury.org/php buster InRelease [6837 B]
Изт:6 https://download.docker.com/linux/debian stretch InRelease [44,8 kB]
Изт:7 https://packages.sury.org/php buster/main amd64 Packages [317 kB]
Игн:4 https://attic.owncloud.org/download/repositories/production/Debian_10  InRelease
Изт:8 https://download.owncloud.org/download/repositories/production/Debian_10  Release [964 B]
Изт:9 https://packages.sury.org/php buster/main i386 Packages [314 kB]
Изт:10 https://download.owncloud.org/download/repositories/production/Debian_10  Release.gpg [481 B]
Грш:10 https://download.owncloud.org/download/repositories/production/Debian_10  Release.gpg
  Следните подписи са невалидни: DDA2C105C4B73A6649AD2BBD47AE7F72479BC94B
Грш:11 https://ookla.bintray.com/debian generic InRelease
  403  Forbidden [IP: 52.39.193.126 443]
Четене на списъците с пакети… Готово
N: Repository 'https://packages.sury.org/php buster InRelease' changed its 'Suite' value from '' to 'buster'
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://download.owncloud.org/download/repositories/production/Debian_10  Release: 

apt-get-update-allow-releaseinfo-change-debian-linux-screenshot

Onwards to upgrade the system up to the latest .deb packages, as usual run:

# apt-get -y update && apt-get upgrade -y

 

and updates should be applied as usual with some prompts on whether you prefer to keep or replace existing service configuration and some information on some general changes that might affect your installed services. In a few minutes and few prompts hopefully your Debian OS should be up to the latest stable.