---
tags:
  - Server
title : Server notes
description : Server notes
date : 2025-01-01
author : Nikola Petrov
---

## To prevent updating of a specific package?
Hold a package:

	sudo apt-mark hold <package-name>

Remove the hold:

	sudo apt-mark unhold <package-name>

Show all packages on hold:

	sudo apt-mark showhold


### USE APT PURGE TO REMOVE APPS

## Dynamic DNS 
DDClient [YouTube](https://www.youtube.com/watch?v=iuDCuUEmKF4) [NameCheap](https://www.namecheap.com/support/knowledgebase/article.aspx/583/11/how-do-i-configure-ddclient/)

Install & Setup Instructions: 
sudo apt-get install ddclient 
sudo nano /etc/ddclient.conf 
daemon=3600 
ssl=yes 
protocol=dyndns2 
use=web, web=myip.dnsomatic.com 
server=updates.dnsomatic.com 
login=Your OpenDNS login 
password=Your OpenDNS Password 
all.dnsomatic.com 

sudo nano /etc/default/ddclient 
run_ipup="false" 
run_daemon="true" 
daemon_interval=3600 

To run it initially: sudo ddclient -daemon=0 -debug -verbose -noquiet

## Shutdown
```
systemctl reboot
systemctl poweroff
```

## Raid
https://linuxconfig.org/linux-software-raid-1-setup

## ssh
in `~/.ssh/authorized_keys` paste your pub key
and then disable password login in `/etc/ssh/sshd_config` change `PasswordAuthentication`
to `no`

```
ssh-keygen -t ed25519
systemctl reload sshd
```


## Network monitor tool
`vnstat --help` 

## python venv in debian
```sh
sudo apt install -y python3-full python3-pip
python -m venv venv
```