Creating an LVM Thin Pool

Documentation: Creating and Managing a Thin Pool for Storage

This guide outlines the steps to create a thin pool and prepare it for use in a Proxmox environment. The following tasks will be covered:

1. Formatting the Disk

2. Creating a Physical Volume (PV) and Volume Group (VG)

3. Creating an LVM Thin Pool

4. Creating a Logical Volume for Storage

5. Formatting the Logical Volume

6. Mounting the Logical Volume

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Task 2: Creating the Thin Pool

Step 1: Format the Disk

Before using a disk (e.g., /dev/sdb), a new partition must be created:

sgdisk -N 1 /dev/sdb

• Command Explanation:

  • sgdisk: Command-line utility to manage GPT partitions.

  • -N 1: Creates a new partition spanning the entire free space on the disk as Partition 1.

  • /dev/sdb: Target disk.

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Step 2: Create Physical Volume (PV) and Volume Group (VG)

Prepare the partition for use with LVM by creating a Physical Volume (PV) and a Volume Group (VG).

Create Physical Volume:

pvcreate --metadatasize 1024M -y -ff /dev/sdb1

• Command Explanation:

  • pvcreate: Initializes a physical volume for LVM.

  • --metadatasize 1024M: Sets metadata size to 1024 MB.

  • -y: Auto-confirm prompts.

  • -ff: Forces the creation even if warnings occur.

  • /dev/sdb1: Partition created in Step 1.

Create Volume Group:

vgcreate --metadatasize 1024M proxvg /dev/sdb1

• Command Explanation:

  • vgcreate: Creates a volume group for LVM.

  • --metadatasize 1024M: Ensures metadata size compatibility with the PV.

  • proxvg: Name of the volume group.

  • /dev/sdb1: Physical volume added to the volume group.

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Step 3: Create an LVM Thin Pool

Define a thin pool in the volume group:

lvcreate -l 100%FREE --poolmetadatasize 1024M --chunksize 256 -T -n proxthin proxvg

• Command Explanation:

  • lvcreate: Creates a logical volume.

  • -l 100%FREE: Uses all remaining free space in the volume group.

  • --poolmetadatasize 1024M: Allocates 1024 MB for pool metadata.

  • --chunksize 256: Sets the chunk size for thin provisioning to 256 KB.

  • -T: Specifies thin pool creation.

  • -n proxthin: Names the thin pool.

  • proxvg: Name of the volume group.

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Step 4: Create a Logical Volume for Storage

Allocate space from the thin pool for storage:

lvcreate -n proxvz -V 400G proxvg/proxthin

• Command Explanation:

  • -n proxvz: Names the logical volume.

  • -V 400G: Creates a virtual volume of 400 GB.

  • proxvg/proxthin: Thin pool from which space is allocated.

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Step 5: Format the Logical Volume with EXT4

Prepare the logical volume for use with the EXT4 filesystem:

mkfs.ext4 /dev/proxvg/proxvz

• Command Explanation:

  • mkfs.ext4: Formats the volume with the EXT4 filesystem.

  • /dev/proxvg/proxvz: Logical volume path.

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Step 6: Mount the Logical Volume

Mount the logical volume to a directory for usage.

Create Mount Directory:

mkdir /media/vz

Update fstab for Persistent Mounting:

echo '/dev/proxvg/proxvz /media/vz ext4 defaults,errors=remount-ro 0 2' >> /etc/fstab

• Command Explanation:

  • Appends mount details to /etc/fstab for automatic mounting at boot.

  • defaults,errors=remount-ro: Default mount options with read-only remount in case of errors.

Apply Mount Configuration:

mount -a

• Command Explanation:

  • Applies all entries in /etc/fstab.

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Notes

• Ensure to replace /media/vz with /media/vmdirectory if that is your preferred mount directory.

• Adjust the volume size (400G) as needed based on your requirements.