Various problems with legacy SSH systems

Case 1

Unable to negotiate with port 22: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1

We solved this problem using the following command:

ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 [email protected];

Case 2

ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 [email protected];
Unable to negotiate with port 22: no matching host key type found. Their offer: ssh-rsa,ssh-dss

We solved this problem using the following command:

ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 -oHostKeyAlgorithms=+ssh-dss [email protected];

EPIC Cyprus – How to Top Up

To top up your account:

  • Dial 202, the 14-digit code#, and press Send/Call.
  • Call for free to 2020, and follow the instructions.

To top up the account of another EPIC subscriber

  • Call 136 and follow the instructions.

How to Free Space from /var/log by Removing Old Log Files


Managing disk space is a critical task for system administrators and users alike. In Linux systems, the /var/log directory can become a source of space consumption due to the accumulation of log files. In this post, we’ll explore a simple command to free up space by deleting old compressed log files and discuss its pros and cons.

The Command

The command find /var/log -type f -name "*.gz" -delete is a powerful way to clean up space in the /var/log directory. Here’s a breakdown of what this command does:

  • find /var/log: Searches in the /var/log directory.
  • -type f: Restricts the search to files.
  • -name "*.gz": Looks for files ending with .gz, which are typically compressed log files.
  • -delete: Deletes the files that match the search criteria.


  1. Efficient Space Management: This command quickly frees up disk space consumed by old, compressed log files, which is essential for the smooth functioning of the system.
  2. Automatable: The command can be automated through a cron job or a script, making regular maintenance easier.
  3. Selective Deletion: It specifically targets .gz files, which are usually older log files that have been compressed, thus keeping the most recent logs intact.


  1. Potential Data Loss: Important historical data in the log files could be lost if they are deleted without proper review.
  2. Lack of Control Over File Age: This command does not discriminate based on the age of the log files. It deletes all .gz files, regardless of how recently they were compressed.
  3. No Backup: The command executes a direct deletion without creating backups, which could be problematic if a file is deleted accidentally.

Best Practices

  • Review Files Before Deletion: Run the command without the -delete flag first to review which files will be deleted.
  • Implement Log Rotation: Set up log rotation to manage log files systematically, compressing and archiving older logs while deleting the oldest ones.
  • Backup Important Logs: Always keep a backup of important logs before running any deletion command.


While the command find /var/log -type f -name "*.gz" -delete is an effective way to free up space in the /var/log directory, it’s important to use it judiciously. Understanding its pros and cons helps in making informed decisions about log management in a Linux environment.

How to speed up Youtube videos more than 2x

Using the playbackRate command to adjust video playback speed on YouTube slightly differs from using it on a standard HTML video element. This is because YouTube uses its player interface, built on top of the HTML5 video API but includes additional features and customizations.

Here’s a step-by-step guide on how to use the playbackRate command on YouTube:

Open YouTube and Select a Video: Navigate to YouTube and open the video you want to adjust.

Access the Browser Console:

  • Open Developer Tools in your browser. This is usually done by right-clicking on the page and selecting “Inspect,” or by pressing Ctrl+Shift+I (Windows/Linux) or Cmd+Option+I (Mac).
  • Switch to the “Console” tab.

Use the Correct JavaScript Command:

  • On YouTube, the video player element can be accessed differently. The command to adjust the playback speed might look like this:
  • document.querySelector('video').playbackRate = X;
  • Replace X with the desired playback speed. For example, 1.5 for 1.5x speed, or 0.75 for 75% of the normal speed.
document.querySelector('video').playbackRate = X;

For regular use, the built-in speed settings in the YouTube player (accessible via the gear icon in the player controls) are the recommended and easiest method to change playback speed. They provide a range of speed options in a user-friendly manner without the need for coding or console commands.

Understanding the playbackRate Command in JavaScript

document.getElementsByTagName("video")[0].playbackRate = X;

In the dynamic world of web development, JavaScript stands as a cornerstone technology, enabling developers and users to interact with web content in powerful ways. Among its many features is the ability to control video playback on web pages. This blog post delves into one such aspect: using the playbackRate command to control the speed of video playback.

What is playbackRate?

The playbackRate property in JavaScript is a feature of the HTML5 Video API. It allows developers to change the speed at which a video plays on a web page. The command document.getElementsByTagName("video")[0].playbackRate = X; is a practical implementation of this feature.

Breaking Down the Command

  • document: This is the root node of the HTML document.
  • getElementsByTagName("video"): This method returns a live HTMLCollection of elements with the specified tag name, in this case, “video”.
  • [0]: Since getElementsByTagName returns a collection, [0] accesses the first video element in the collection. If there are multiple videos, changing the index accesses different videos.
  • playbackRate: This property sets or returns the current playback speed of the video. 1 is the normal speed, values greater than 1 increase the speed, and values between 0 and 1 slow it down.
  • X: This represents the desired playback speed. For instance, setting X to 1.5 would make the video play at 1.5 times its normal speed.

Practical Use Cases

  • Educational Content: Speed up or slow down instructional videos to match the learner’s pace.
  • Accessibility: Adjust video speed for viewers who need more time to process visual content.
  • Entertainment: Speed through slow sections of videos or slow down for detailed analysis of scenes.

How to Implement

  1. Identify the Video: Ensure the video element is correctly targeted, especially in pages with multiple videos.
  2. Set the Playback Speed: Assign the desired speed to playbackRate. For example, document.getElementsByTagName("video")[0].playbackRate = 1.5; speeds up the first video by 50%.
  3. Test and Debug: Verify that the speed adjustment works across different browsers and devices.

Best Practices

  • User Control: Ideally, provide a user interface for viewers to adjust the speed according to their preference.
  • Browser Compatibility: Test the functionality in various browsers to ensure consistent behavior.
  • Fallbacks: In cases where playbackRate is not supported, consider alternative methods or inform the user.


The playbackRate property in JavaScript offers a simple yet powerful tool for enhancing the video viewing experience on web pages. By understanding and utilizing this command, developers can provide more dynamic and user-friendly web applications. Whether it’s for educational purposes, accessibility, or just personal preference, the ability to control video playback speed is an invaluable feature in today’s web landscape.