https://drive.google.com/file/d/1rGjhicPz_wHxEHCnz5OHrTY1XznRYTKS/view?usp=sharing

1. Understanding Thin Provisioning

Key Concepts

• Thin Pool: A shared storage pool that allocates space on-demand.
• Thin Volumes: Virtual volumes that overcommit space (e.g., create 20GB of thin volumes on a 15GB pool).
• Benefits:
  • Efficient storage utilization
  • Instant volume creation
  • Snapshots with minimal overhead

⚠️ Critical Warning:

Thin provisioning risks pool exhaustion—monitor usage closely!

2. Lab Setup: Create Thin Pool

Prepare Disk

# Create 20GB partition on /dev/sdb
sudo fdisk /dev/sdb
# Commands: n → p → 1 → [Enter] → +20G → w
sudo partprobe

# Create PV and VG with custom extent size (32MB)
sudo pvcreate /dev/sdb1
sudo vgcreate -s 32M vg_thin /dev/sdb1    # -s = physical extent size
sudo vgdisplay vg_thin

💡 Why 32MB extents?

Larger extents reduce metadata overhead for large thin pools.

Create Thin Pool

# Create 15GB thin pool
sudo lvcreate -L 15G --thinpool thin_pool vg_thin
sudo lvs    # Shows thin_pool (type: thin-pool)

3. Create Thin Volumes

Create Three 5GB Thin Volumes

# Note: Correct VG name is "vg_thin" (not "vg-thin")
sudo lvcreate -V 5G --thin -n thin_vol_client1 vg_thin/thin_pool
sudo lvcreate -V 5G --thin -n thin_vol_client2 vg_thin/thin_pool
sudo lvcreate -V 5G --thin -n thin_vol_client3 vg_thin/thin_pool
sudo lvs    # Shows thin volumes (type: thin)

✅ Key Point:

• V = virtual size (logical size visible to OS)

Actual space used = only what’s written