🛠️ Full System Partitioning with LVM on CentOS (with `/boot/efi`, `/boot`, `/var`, `/swap`, `/opt`, `/home`, `/root`, and `/recovery`)

This tutorial will guide you through setting up a complete CentOS system with multiple partitions, utilizing LVM (Logical Volume Management) where applicable. You'll configure /boot/efi, /boot (without LVM), and use LVM for /var, /swap, /opt, /home, /root, and /recovery.

📋 Table of Contents

System Overview 💡
Boot into CentOS Installation Mode 🖥️
Partitioning Disk Layout 📊
Creating Physical Volumes (PV) for LVM 📦
Creating Volume Groups (VG) for LVM 📚
Creating Logical Volumes (LV) 🔧
Formatting the Partitions and Logical Volumes 📝
Mounting Partitions and Logical Volumes 🗄️
Updating /etc/fstab for Automatic Mounting on Boot 🔄
Verifying the Setup ✅
Summary Script 📜

1. System Overview 💡

For this installation, we will create the following partitions:

Non-LVM Partitions:
/boot/efi (EFI partition)
/boot (Standard boot partition)
LVM Partitions:
/var (for system logs and temporary data)
/swap (swap space)
/opt (for optional software installations)
/home (user directories)
/root (root user directory)
/recovery (for backups or recovery data)

2. Boot into CentOS Installation Mode 🖥️

Insert your CentOS installation media (USB or DVD).
Boot the system and choose the Installation Mode.
At the installation summary screen, select Manual Partitioning.

3. Partitioning Disk Layout 📊

Step 1: Create `/boot/efi` (Non-LVM)

Size: 512MB (Recommended)
Filesystem: EFI System Partition (/boot/efi)

Step 2: Create `/boot` (Non-LVM)

Size: 1GB
Filesystem: ext4 (/boot)

Step 3: Create an LVM Partition for All Other Mount Points

Create a Physical Volume (PV) on the remaining disk space for LVM. We will do this in the next section.
Once the LVM is created, we will assign the following mount points using logical volumes:
/var: 5GB (ext4)
/swap: 4GB (swap partition)
/opt: 3GB (ext4)
/home: 10GB (ext4)
/root: 5GB (ext4)
/recovery: 5GB (ext4)

4. Creating Physical Volumes (PV) for LVM 📦

Once your partitions for /boot and /boot/efi are created, you can allocate the remaining disk space for LVM. Open the terminal or use a virtual console (press Ctrl + Alt + F2) and run the following commands:

# Stage 1: Create a physical volume on the remaining disk space
pvcreate /dev/sda3  # Replace with your actual disk partition (usually after /boot)

# Verify the physical volume creation
pvs

5. Creating Volume Groups (VG) for LVM 📚

Next, we will create a Volume Group (VG) to manage all the logical volumes:

# Stage 2: Create a volume group named vg_main
vgcreate vg_main /dev/sda3

# Verify the volume group
vgs

6. Creating Logical Volumes (LV) 🔧

Now, create Logical Volumes (LV) for each of the mount points (/var, /swap, /opt, /home, /root, /recovery):

# Stage 3: Create logical volumes for each mount point
lvcreate -L 5G -n lv_var vg_main     # /var
lvcreate -L 4G -n lv_swap vg_main    # /swap
lvcreate -L 3G -n lv_opt vg_main     # /opt
lvcreate -L 10G -n lv_home vg_main   # /home
lvcreate -L 5G -n lv_root vg_main    # /root
lvcreate -L 5G -n lv_recovery vg_main # /recovery

# Verify the logical volumes
lvs

7. Formatting the Partitions and Logical Volumes 📝

Now that we have the logical volumes created, format them using the appropriate filesystems:

# Stage 4: Format non-LVM partitions
mkfs.vfat /dev/sda1  # /boot/efi
mkfs.ext4 /dev/sda2  # /boot

# Format the LVM partitions
mkfs.ext4 /dev/vg_main/lv_var     # /var
mkswap /dev/vg_main/lv_swap       # /swap
mkfs.ext4 /dev/vg_main/lv_opt     # /opt
mkfs.ext4 /dev/vg_main/lv_home    # /home
mkfs.ext4 /dev/vg_main/lv_root    # /root
mkfs.ext4 /dev/vg_main/lv_recovery # /recovery

8. Mounting Partitions and Logical Volumes 🗄️

Once the filesystems are created, we can now mount each partition:

# Stage 5: Mount non-LVM partitions
mount /dev/sda2 /mnt/boot       # /boot
mkdir -p /mnt/boot/efi
mount /dev/sda1 /mnt/boot/efi   # /boot/efi

# Mount LVM partitions
mount /dev/vg_main/lv_var /mnt/var        # /var
mount /dev/vg_main/lv_opt /mnt/opt        # /opt
mount /dev/vg_main/lv_home /mnt/home      # /home
mount /dev/vg_main/lv_root /mnt/root      # /root
mount /dev/vg_main/lv_recovery /mnt/recovery # /recovery

# Enable swap
swapon /dev/vg_main/lv_swap               # /swap

9. Updating `/etc/fstab` for Automatic Mounting on Boot 🔄

To ensure the partitions are automatically mounted during boot, update the /etc/fstab file:

# Stage 6: Open /etc/fstab in an editor
nano /mnt/etc/fstab

# Add the following entries

/dev/sda1  /boot/efi   vfat    defaults    0 0
/dev/sda2  /boot       ext4    defaults    0 2
/dev/vg_main/lv_var    /var     ext4       defaults    0 2
/dev/vg_main/lv_opt    /opt     ext4       defaults    0 2
/dev/vg_main/lv_home   /home    ext4       defaults    0 2
/dev/vg_main/lv_root   /root    ext4       defaults    0 2
/dev/vg_main/lv_recovery /recovery ext4    defaults    0 2
/dev/vg_main/lv_swap   none     swap       sw          0 0

10. Verifying the Setup ✅

Finally, verify that all partitions are mounted correctly:

# Stage 7: Check the partition table and mounted partitions
lsblk

# Verify swap
swapon --show

# Reboot and check if everything mounts correctly
reboot

11. Summary Script 📜

Here’s a summary script that encapsulates the steps in a single script format with stage comments:

#!/bin/bash

# Stage 1: Create Physical Volume
pvcreate /dev/sda3

# Stage 2: Create Volume Group
vgcreate vg_main /dev/sda3

# Stage 3: Create Logical Volumes
lvcreate -L 5G -n lv_var vg_main
lvcreate -L 4G -n lv_swap vg_main
lvcreate -L 3G -n lv_opt vg_main
lvcreate -L 10G -n lv_home vg_main
lvcreate -L 5G -n lv_root vg_main
lvcreate -L 5G -n lv_recovery vg_main

# Stage 4: Format Partitions
mkfs.vfat /dev/sda1      # /

boot/efi
mkfs.ext4 /dev/sda2      # /boot
mkfs.ext4 /dev/vg_main/lv_var
mkswap /dev/vg_main/lv_swap
mkfs.ext4 /dev/vg_main/lv_opt
mkfs.ext4 /dev/vg_main/lv_home
mkfs.ext4 /dev/vg_main/lv_root
mkfs.ext4 /dev/vg_main/lv_recovery

# Stage 5: Mount Partitions
mount /dev/sda2 /mnt/boot
mkdir -p /mnt/boot/efi
mount /dev/sda1 /mnt/boot/efi
mount /dev/vg_main/lv_var /mnt/var
mount /dev/vg_main/lv_opt /mnt/opt
mount /dev/vg_main/lv_home /mnt/home
mount /dev/vg_main/lv_root /mnt/root
mount /dev/vg_main/lv_recovery /mnt/recovery
swapon /dev/vg_main/lv_swap

# Stage 6: Update /etc/fstab
cat <<EOL >> /mnt/etc/fstab
/dev/sda1  /boot/efi   vfat    defaults    0 0
/dev/sda2  /boot       ext4    defaults    0 2
/dev/vg_main/lv_var    /var     ext4       defaults    0 2
/dev/vg_main/lv_opt    /opt     ext4       defaults    0 2
/dev/vg_main/lv_home   /home    ext4       defaults    0 2
/dev/vg_main/lv_root   /root    ext4       defaults    0 2
/dev/vg_main/lv_recovery /recovery ext4    defaults    0 2
/dev/vg_main/lv_swap   none     swap       sw          0 0
EOL

# Stage 7: Verify Setup
lsblk
swapon --show

📝 Conclusion

This guide has provided a comprehensive approach to partitioning a CentOS system using LVM. By following the steps outlined, you can ensure a robust and flexible partitioning scheme tailored to your needs. Don't forget to back up your data regularly! 🚀

🛠️ Full System Partitioning with LVM on CentOS (with /boot/efi, /boot, /var, /swap, /opt, /home, /root, and /recovery)