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Logical Volume Manager

LVM (Logical Volume Manager) is a storage management solution in Linux that provides a flexible and advanced way to manage disk storage. Instead of using Windows, partitioning disk is a lot easier with linux especially with LVM. Instead partitioning disks into fixed sizes, LVM allows dynamic resizing, snapshot creation, and volume grouping.

Physical Volume (PV)​

A Physical Volume (PV) is a raw storage device (disk or partition) initialized for LVM use.

  • Example: /dev/sdb, /dev/sdc
  • Create a PV: 
    sudo pvcreate /dev/sdb
  • View existing PVs: 
    sudo pvdisplay

Volume Group (VG)​

A Volume Group (VG) is a pool of storage combining multiple PVs.

  • Create a VG named my_vg: 
    sudo vgcreate my_vg /dev/sdb
  • View existing VGs: 
    sudo vgdisplay

Logical Volume (LV)​

A Logical Volume (LV) is a resizable virtual partition created from a VG.

  • Create an LV named my_lv with 5GB size: 
    sudo lvcreate -L 5G -n my_lv my_vg
  • View existing LVs: 
    sudo lvdisplay

Formatting and Mounting an LV​

1. Format the LV​

  • Format with XFS: 
    sudo mkfs.xfs /dev/my_vg/my_lv
  • Format with ext4: 
    sudo mkfs.ext4 /dev/my_vg/my_lv

2. Mount the LV​

  • Create a mount point: 
    sudo mkdir /mnt/my_storage
  • Mount the LV: 
    sudo mount /dev/my_vg/my_lv /mnt/my_storage
  • Verify: 
    df -h

Making the Mount Persistent Across Reboots​

  • Edit /etc/fstab: 
    sudo nano /etc/fstab
  • Add this line: 
    /dev/mapper/my_vg-my_lv /mnt/my_storage xfs defaults 0 0
  • Save and apply changes: 
    sudo mount -a

Managing Logical Volumes​

1. Extend an LV​

  • Increase LV size by 2GB: 
    sudo lvextend -L +2G /dev/my_vg/my_lv
  • Resize filesystem: 
    sudo xfs_growfs /mnt/my_storage  # For XFS
    sudo resize2fs /dev/my_vg/my_lv  # For ext4

2. Remove an LVM Setup (Optional)​

  • Unmount the LV: 
    sudo umount /mnt/my_storage
  • Remove the LV: 
    sudo lvremove /dev/my_vg/my_lv
  • Remove the VG: 
    sudo vgremove my_vg
  • Remove the PV: 
    sudo pvremove /dev/sdb