Category: Proxmox

Troubleshooting Proxmox clusters and restoring the LXC container

Posted on by soban

Managing Proxmox clusters can sometimes present technical difficulties, such as inconsistencies in cluster configuration or issues with restoring LXC containers. Finding and resolving these issues is crucial for maintaining the stability and performance of the virtualization environment. In this article, I present a detailed guide on how to diagnose and resolve an issue with an unreachable node and how to successfully restore an LXC container.

Before you begin any actions, make sure you have a current backup of the system.

Diagnosing the State of the Proxmox Cluster

and:

To understand the state of the cluster, execute the following command on the node-up-page-04 node:

Expected output:

Then check the detailed cluster information with the following command:

Expected output:

Removing the Container Configuration File and Cleaning Data

I discovered that the configuration file for container 107 still exists on the cluster’s file system at the path:

Output:

To remove this file and any remaining data associated with the detached node, execute:

Restoring the Container

After removing the configuration file, I restored the LXC container on the node-up-page-04 node using the command:

Output:

The restoration process was successful, and the container was ready for use. This case illustrates the importance of thorough diagnostics and configuration file management in Proxmox when working with clusters. Regular reviews of configurations are advisable to avoid inconsistencies and operational issues in the future.

Extending SWAP space on Proxmox using lvreduce

Posted on by soban

Introduction

Managing SWAP memory is a key element in administering Linux operating systems, especially in virtualization environments like Proxmox. SWAP acts as “virtual memory” that can be used when the system’s physical RAM is full. In this article, we will show how to increase SWAP space on a Proxmox server, using the lvresize tool to free up disk space that can then be allocated to SWAP.

Problem Overview

A user wants to increase SWAP space from 8 GB to 16 GB, but encounters the problem of lacking available space in the LVM volume group, which is required to increase SWAP.

Step 1: Checking Available Space

The command vgs displays the volume groups along with their sizes and available space.

Step 2: Reducing the Volume

Suppose there is a root volume of 457.26 GB, which can be reduced to free up an additional 8 GB for SWAP. Before reducing the volume, it is necessary to reduce the file system on this volume.

However, in the case of the XFS file system, reduction must occur offline or from a live CD.

Step 3: Using lvreduce

This command reduces the root volume by 8 GB, which is confirmed by a message about the volume size change.

Step 4: Deactivating SWAP

Before starting changes in SWAP size, SWAP must first be turned off using the above command.

Step 5: Expanding SWAP

The above commands first increase the SWAP space, then format it and reactivate it.

Finally, we verify the active SWAP areas using the above command to ensure everything is configured correctly.

This process shows how you can flexibly manage disk space on Proxmox servers, adjusting the size of SWAP depending on needs. Using lvreduce requires caution, as any operation on partitions and volumes carries the risk of data loss, therefore it is always recommended to make backups before proceeding with changes.

Automating the Backup Process in Proxmox: Practical Crontab Script and Configuration

Posted on by soban

In today’s world, where data is becoming increasingly valuable, proper backup management is crucial for the security of information systems. In this article, I present an effective way to automate the backup of key configuration files in Proxmox-based systems using a simple bash script and Crontab configuration.

Bash Script for Backup of the /etc Directory

The /etc file contains critical system configuration files that are essential for the proper functioning of the operating system and various applications. Loss or damage to these files can lead to serious problems. Below, I present an effective script, backup-etc.sh, that allows for the automated backup of this directory:

This script performs the following operations:

  1. Generates the current date and time, which are added to the name of the archive to easily identify individual copies.
  2. Uses the tar program with zstd compression to create an archived and compressed copy of the /etc directory.
  3. Removes archives older than 100 days from the /var/lib/vz/dump/ location, thus ensuring optimal disk space management.

Adding Script to Crontab

To automate the backup process, the script should be added to crontab. Below is a sample configuration that runs the script daily at 2:40 AM:

Redirecting output to /dev/null ensures that operations are performed quietly without generating additional output to standard output.

Download the Script from soban.pl

The backup-etc.sh script is also available for download from the soban.pl website. You can download it using the following wget command and immediately save it as /root/backup-etc.sh:

With this simple command, the script is downloaded from the server and granted appropriate executable permissions.

Benefits and Modifications

The backup-etc.sh script is flexible and can be easily modified to suit different systems. It is default placed in the /var/lib/vz/dump/ folder, which is a standard backup storage location in Proxmox environments. This simplifies backup management and can be easily integrated with existing backup solutions.

By keeping backups for 100 days, we ensure a balance between availability and disk space management. Old copies are automatically deleted, minimizing the risk of disk overflow and reducing data storage costs.

Summary

Automating backups using a bash script and Crontab is an effective method to secure critical system data. The backup-etc.sh script provides simplicity, flexibility, and efficiency, making it an excellent solution for Proxmox system administrators. I encourage you to adapt and modify this script according to your own needs to provide even better protection for your IT environment.

Simplified Proxmox VE 8 Installation on Debian 12 Bookworm

Posted on by soban

Proxmox VE is a comprehensive, open-source server management platform that seamlessly integrates KVM hypervisor and LXC containers. Today, we present a streamlined process for installing Proxmox VE 8 on Debian 12 Bookworm, based on the official guidance from the Proxmox VE Installation Guide.

Prerequisites

  • A fresh Debian 12 Bookworm installation.
  • A user with sudo privileges.
  • Internet connectivity.

Installation Scripts

We’ve divided the installation into two scripts. The first script prepares your system and installs the Proxmox VE kernel. The second script continues the process after a system reboot, installing the remaining Proxmox VE packages.

Remember, all these commands need to be executed from the root user level, so:

First Part: System Preparation and Kernel Installation

Start by downloading the first script which prepares your system and installs the Proxmox VE kernel:

Run the script with the following command:

Here is the content of the script:

After running the first script, your system will reboot. At this stage, you may encounter a few dialogs from the system, which are part of the normal package configuration steps. For this simplified installation, you can accept the default options by pressing Enter.

Screenshots during Installation

The selection of GRUB installation configuration.

GRUB Configuration – A new version of the GRUB bootloader configuration file is available. It’s recommended to keep the local version currently installed unless you are aware of the changes. As with the previous dialogs, pressing Enter will select the default action.

The selection of postfix installation configuration.

Postfix Configuration – This dialog appears when installing the postfix package, which is a mail transport agent. The default option “Internet Site” is suitable for most cases. Pressing Enter accepts this configuration.

Setting the system mail name.

System Mail Name – Here you specify the FQDN (Fully Qualified Domain Name) for the system mail. The default value is usually adequate unless you have a specific domain name for your server. Again, pressing Enter will continue with the default configuration.

There might be issues encountered towards the end of the first script installation, such as:

However, the second part of the script, executed after the reboot, addresses these problems.
After a successful reboot of the machine, log into the system and proceed to the second script.

Second Part: Completing Proxmox VE Installation

After your system has rebooted, proceed with downloading the second script:

Execute the second part of the installation with the command:

This is the content of the second script:

Once the second script completes, you will be able to access the Proxmox VE web interface using the URL displayed at the script’s conclusion. Log in with the ‘root’ username and your root password.

Upon loading the page, you may encounter a certificate trust error – this is normal at this stage, and you can safely accept that it is unsafe and proceed to access the page for managing Proxmox. If you don’t know the root password, you can reset it by executing ‘passwd‘ as root. Good luck!

Checking the disk for errors and bad sectors

Posted on by soban

This script helps to notify me by e-mail about the condition of the disk. Remember to indicate the disk accordingly – in this case it is “/dev/sda” and change the e-mail address from “soban@soban.pl” to your own. Save the script in “/root/checkbadsector.sh“:

You can also download it from https://soban.pl/bash/checkbadsector.sh:

Remember to grant permission to perform it:

On my server I added it once a month so that it would be performed periodically in the crontab:

You should receive an email similar to the one below:

Good luck and I wish you no errors!

E-mail notification about new updates Proxmox

Posted on by soban

This script send you e-mail notification about new updates:

You can download the script from:

You should set the correct e-mail address in the script, for now it is soban@soban.pl
Notification it’s looks something like that:

Should the script be executed:

Also added to the crontab, every day to extend a new update:

Remember don’t to upgrade your system on Friday! Good luck!