Timezone, Hostname & Swap

OS Covered: (AlmaLinux / RockyLinux / CentOS / CloudLinux)

📌 1. Timezone Setup

Step 1: List all available timezones

timedatectl list-timezones

Step 2: Set your timezone
(Example: Dhaka → Asia/Dhaka)

timedatectl set-timezone Asia/Dhaka

Step 3: Verify timezone

timedatectl

---

📌 2. Hostname Setup

Step 1: Set temporary hostname (until reboot)

hostnamectl set-hostname server1.example.com

Step 2: Make it permanent

nano /etc/hostname

এখানে লিখুন:

server1.example.com

Step 3: Update hosts file

nano /etc/hosts

Add line (replace with your server IP + hostname):

192.168.1.100   server1.example.com server1

Step 4: Verify

hostnamectl

---

📌 3. Swap Setup

👉 Swap memory use হয় যখন RAM full হয়ে যায়। Recommended: 2GB+ swap.

Step 1: Check if swap already exists

swapon --show
free -h

Step 2: Create swap file (example: 2GB)

fallocate -l 2G /swapfile

Step 3: Secure permissions

chmod 600 /swapfile

Step 4: Format swap

mkswap /swapfile

Step 5: Enable swap

swapon /swapfile

Step 6: Make it permanent

echo '/swapfile none swap sw 0 0' | tee -a /etc/fstab

Step 7: Verify swap

swapon --show
free -h

---

✅ এখন তোমার server এ timezone, hostname, আর swap fully configure হয়ে গেছে।