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Linux Mint with Custom LVM on LUKS

Overview​

The current Linux Mint installer doesn't support custom partitions when setting up a new machine with LUKS encryption using LVM. I prefer having a separate partition for my home directory and a backup partition for Timeshift, so that reinstalling or fixing issues won't overwrite my home directory.

I found several approaches to achieve this. One method involves setting up partitions first and then using the installer to select them, but this requires extensive post-installation configuration to get boot working with the encrypted drive.

I discovered this blog which explains how to repartition your drive after installation. Combined with my guide on setting up hibernation, I created this documentation to help remember how to install a fresh copy of Linux Mint with LVM and LUKS.

Tested on: Linux Mint 22 Cinnamon

Partition Layout​

For this guide, I'm working with a 1TB drive that will be split into the following logical volumes:

  • Root - 100GB (system files and applications)
  • Swap - 32GB (for hibernation support)
  • Home - 700GB (user files and documents)
  • Backup - 100GB (Timeshift snapshots)
  • Unallocated - ~68GB (reserved for future expansion)

This setup ensures that system snapshots and user data remain separate, making system recovery much easier.

Installation Guide​

Step 1: Initial Linux Mint Installation​

Start the Linux Mint installation process as normal:

  1. Boot from your Linux Mint installation media
  2. Follow the installation wizard (language, keyboard layout, etc.)
  3. When you reach the Installation type screen:
    • Select "Erase disk and install Linux Mint"
    • Click "Advanced features"
    • Enable both options:
      • ✓ Use LVM with the new Linux Mint installation
      • ✓ Encrypt the new Linux Mint installation for security
    • Click Continue
  4. Enter a strong encryption password when prompted
  5. Complete the rest of the installation (timezone, user account, etc.)
  6. When installation finishes, do NOT click "Restart Now" - we'll repartition first

Important: Do NOT reboot after installation completes. We need to repartition before the first boot.

Step 2: Access Root Terminal​

After installation finishes, open a terminal and switch to root:

sudo -i

This gives you administrative privileges needed for disk operations.

Step 3: Check Current Disk Layout​

View your current partition structure:

lsblk -f

This displays your filesystem layout. You should see your encrypted volume group (typically vgmint) with a large root partition consuming most of the space.

Step 4: Resize Root Partition​

Shrink the root partition from its default size (nearly full disk) to 100GB:

lvresize -L 100G --resizefs vgmint/root

What this does:

  • -L 100G sets the logical volume size to exactly 100GB
  • --resizefs automatically resizes the filesystem to match
  • This frees up ~900GB for our other partitions

Step 5: Resize Swap Partition​

The default swap is usually small (a few GB). We need to increase it to 32GB for hibernation:

lvresize --verbose -L +32G /dev/mapper/vgmint-swap_1

What this does:

  • -L +32G adds 32GB to the current swap size
  • --verbose shows detailed progress information
  • This ensures enough swap space for RAM contents during hibernation

Note: For hibernation to work, swap should be at least equal to your RAM size. Adjust accordingly.

Step 6: Create Home Partition​

Create a new logical volume for your home directory:

lvcreate -L 700G vgmint -n home

What this does:

  • -L 700G creates a 700GB logical volume
  • vgmint is the volume group name
  • -n home names the new volume "home"

Step 7: Create Backup Partition​

Create a logical volume for Timeshift backups:

lvcreate -L 100G vgmint -n backup

What this does:

  • Creates a dedicated 100GB space for system snapshots
  • Keeps backups separate from user data
  • Prevents backups from filling up your home partition

Step 8: Format New Partitions​

Format both new partitions with the ext4 filesystem:

mkfs.ext4 /dev/vgmint/backup
mkfs.ext4 /dev/vgmint/home

What this does:

  • Creates ext4 filesystems on both logical volumes
  • ext4 is the standard Linux filesystem with good performance and reliability

Step 9: Mount Partitions​

Create mount points and mount your partitions:

mkdir /mnt/{root,home}
mount /dev/vgmint/root /mnt/root/
mount /dev/vgmint/home /mnt/home/

What this does:

  • Creates temporary directories to access the filesystems
  • Mounts root and home so we can configure them

Step 10: Move Home Directory Contents​

Move the existing home directory contents from the root partition to the new home partition:

mv /mnt/root/home/* /mnt/home/

What this does:

  • Transfers all user files and directories from the old location to the new home partition
  • Preserves your user account settings and any files created during installation
  • Without this step, your home directory would be empty on first boot

Step 11: Update fstab​

Add the home partition to the system's fstab file so it mounts automatically at boot:

echo "/dev/mapper/vgmint-home /home           ext4    defaults        0 2" >> /mnt/root/etc/fstab

What this does:

  • Appends a mount entry to /etc/fstab
  • Ensures /home partition mounts automatically at startup
  • The 0 2 values enable filesystem checks during boot

Step 12: Clean Up and Prepare for Reboot​

Unmount the partitions and deactivate the volume group:

umount /mnt/root
umount /mnt/home
swapoff -a
lvchange -an vgmint

What this does:

  • Safely unmounts all mounted filesystems
  • Turns off swap
  • Deactivates the volume group to prevent conflicts
  • Ensures everything is properly closed before reboot

Step 13: Reboot​

Now you can safely reboot into your new system:

reboot

Enter your LUKS encryption password at boot, then log in normally.

Verification​

After rebooting, verify your partition setup:

lsblk -f
df -h

You should see:

  • Root (/) mounted with ~100GB
  • Home (/home) mounted with ~700GB
  • Swap available with 32GB
  • Backup partition ready for Timeshift configuration

Setting Up Timeshift​

To complete your backup solution:

  1. Install Timeshift (if not already installed): sudo apt install timeshift
  2. Launch Timeshift and select RSYNC mode
  3. Choose the backup partition as your snapshot location
  4. Configure your backup schedule (daily, weekly, monthly)
  5. Create your first snapshot

Additional Resources​

Conclusion​

This setup gives you the best of both worlds: the security of full-disk encryption with LUKS, and the flexibility of custom LVM partitions. Your home directory and system backups are now isolated, making system recovery and upgrades much safer and more manageable.