nam huy linux blog

What is Phishing attack / phishing email Phishing email, or phishing attack, is tricking people into telling you confidential information (password, social security number, credit card number, bank login information, address, date of birth, etc.). It could be in form of a phone call, website, email. They will will pretend to be someone or something the person normally would give confidential…

Setting up a small business phone over IP (Voice over Internet Protocol) system can be a cost-effective and efficient way to manage your team’s communication needs. Here’s a step-by-step guide to help you set it up: **Hardware Requirements:** 1. **IP Phones:** You’ll need at least one IP phone for each employee who will use the system. Popular options include Cisco, Polycom, or Yealink. 2.…

VoIP (Voice over Internet Protocol) is a technology that allows users to make voice calls using the internet rather than traditional analog telephone lines or cellular networks. VoIP converts audio signals into digital data packets, which are transmitted over the internet and then converted back into sound at the receiving end. Here’s how it works: 1. **Digital Signal Processing:** When you place…

To host a WordPress website, you will need a domain name, a web hosting service that supports WordPress, and an FTP client or file manager (if your hosting service does not have one built-in). Here’s a step-by-step guide: 1. Choose a Domain Name: Select a domain name that represents your website and is easy to remember. You can purchase a domain name from registrars like Namecheap, Porkbun, or…

When I migrate a Proxmox CT (LXC Container) from one node to another node in my homelab clusster, for some reason the migration could not be completed. It keeps giving me error (TASK ERROR: CT is locked (migrate)). I could not start/stop or do anything with that CT, even after I restarted the node. I ran the “qm unlock” command (qm manages the qemu VMs) on my pve3 node but I got .conf file does…

user www-data; worker_processes auto; pid /run/nginx.pid; include /etc/nginx/modules-enabled/*.conf; events { worker_connections 768; multi_accept on; } http { ## Basic Settings ## sendfile on; tcp_nopush on; tcp_nodelay on; keepalive_timeout 10s; types_hash_max_size 2048; server_tokens off; server_names_hash_bucket_size 64; server_name_in_redirect off; include /etc/nginx/mime.types; default_type…

How to configure Nginx 1.8 on CentOS 7

Following up my previous tutorial How to install LEMP Server (Nginx 1.8, MariaDB 10.1, PHP-FPM 7) on CentOS 7; In that tutorial I show you how install Nginx 1.8, MariaDB 10.1, and PHP-FPM 7 on CentOS 7, but without showing you how to configure them to make them work properly. In this tutorial I will show you how to configure Nginx 1.8 properly on CentOS 7. Please read and follow my tutorial step…

How to fix nginx client request body is buffered to a temporary file

“client request body is buffered to a temporary file” is one of Nginx’s warn which I found While auditing my web server. Nginx’s warn is anything that can potentially cause a problem. There are “warns” that are not important, some are important to look into and fix them. In the log I got, while editing WordPress’s theme, there was not enough in-memory buffer reserved for editing / saving theme…

How to fix upstream timed out (110: Connection timed out)

I’m seeing timed out errors lately with Nginx web server, after looking into Nginx’s log I found out there are a few “upstream timed out (110: Connection timed out) while reading response header from upstream” error. If you have Nginx with PHP-FPM setup, and heavy PHP scripts like WordPress with lots of WordPress’s plugins, you will properly going to see 504 gateway time-out error in your web…

Linux Crontab stands for “cron table”, or Cron Job (Scheduled Task) is a great Unix utility for any Linux sysadmin to run regular schedule jobs in the background automatically. cron is the system process which will perform tasks that you set at specified time. You can set cron to run recurring or even one-time to perform system maintenance, administration, or run specific task/script at specific…

How to install dig, host, nslookup on CentOS 7

dig command is a tool for querying DNS nameservers on Linux operating system. host is another tool for performing DNS lookups. nslookup is also a tool for querying DNS to obtain domain name, IP address, or DNS records. Those are great little tools for any sysadmin, but unfortunately those tools aren’t installed by default on CentOS 7. dig, host, and nslookup are a part of the BIND utilities, to…

How to change timezone, date, time on CentOS 7

Have different time between your local time & remote server can be problematic, especially when it comes to reading logs. Say my time zone is US Pacific yet one of my VPS is set to US Eastern or else where, it is very difficult to know exactly when things happened due to time differences. In this tutorial I’m going to show you how to change date, time, timezone on CentOS 7.

CentOS 7 timezone…

How to install Webmin on CentOS 7

I have upgraded some of my systems from Centos 6 to Centos 7. There are many new features in Centos 7 that Centos 6 does not have, but the way Centos 7 work is sort of different from Centos 6. Back to our topic, I’m going to show you how to install Webmin on Centos 7 / RHEL 7. Webmin is a great open source web based control panel for Linux. You can pretty much mange everything on your Centos 7…

How to install fail2ban on CentOS 7

I have a spare VPS for testing purpose, the last few days I have not login to it. Today after I login to that VPS I see there are 57410 failed login attempts just in a few days, just wow. To prevent people/bots brute force your server, fail2ban is one of the solution for it. Fail2ban can be configured to monitor any service that writes login attempts to a log file that makes too many password…

iptables script for CentOS 6

iptables is a firewall program that le system administrator interact and configure at the command line the tables (firewall rules) by the Linux kernel firewall (netfilter is a kernel module). I can’t explain in detailed about iptables here since its way too much information, but I made a simple iptables script for CentOS 6 that you can run on your system without too much knowledge about it (basic…

How to install LEMP Server (Nginx 1.8, MariaDB 10.1, PHP-FPM 7) on CentOS 7

LEMP stacks are an open source platform for applications that is compatible with the LAMP (refers to a Linux-based operating system, the Apache web server, the MySQL database server, and the PHP programming language). LEMP replaces Apache with Nginx which is  light-weight and its ability to scale easily on minimal hardware. This tutorial (How to install LEMP Server (Nginx 1.8, MariaDB 10.1,…

How to install OpenVPN Access Server on CentOS 7

A VPN or Virual Private Networkis a secure tunnel between two devices to add security and privacy to private and public networks. All VPN connection is encrypted to ensure all of the data you are sending and receiving is secured from spying eyes. OpenVPN is an open source software which let you tunnel any IP sub-network or virtual Ethernet adapter over a single UDP or TCP port, and I’m going to…