Master LVM: Create, Resize, and Delete Logical Volumes on Linux

1. Prepare physical devices

List the target disks:

lsblk /dev/sdb /dev/sdc

2. Create physical volumes

Initialize the disks as physical volumes: pvcreate /dev/sdb /dev/sdc Verify with:

pvs
pvdisplay /dev/sdb
pvdisplay /dev/sdc

3. Create a volume group

Create a volume group named myvg01 and add the physical volumes: vgcreate myvg01 /dev/sdb /dev/sdc Check the group:

vgs myvg01
vgdisplay myvg01

4. Create logical volumes

Parameter explanation: -n: logical volume name -L: size in absolute units (e.g., 5G) -l: size in extents or percentage (e.g., 100 extents or 50%FREE)

Examples:

lvcreate -n mylv01 -L 5G myvg01

lvcreate -n mylv02 -l 100 myvg01

lvcreate -n mylv03 -l 50%FREE myvg01

View logical volumes:

lvs /dev/myvg01/mylv01
lvs /dev/myvg01/mylv02
lvs /dev/myvg01/mylv03

5. Format logical volumes

Format mylv01 with XFS:

mkfs.xfs /dev/myvg01/mylv01

6. Mount and use

mkdir /funlyp-lv01
mount /dev/myvg01/mylv01 /funlyp-lv01
df -Th | grep funlyp
touch /funlyp-lv01/lvm_practice.log

7. Dynamic expansion

Task: The partition is too small, how to expand?

Steps:

Identify the mounted logical volume (e.g., /dev/mapper/myvg01-mylv01).

Check free space in the volume group with vgs myvg01.

If free space exists, extend the logical volume and grow the filesystem.

Example – add 5 GiB:

lvextend -L +5G /dev/myvg01/mylv01
xfs_growfs /dev/myvg01/mylv01

Further expansion to 20 GiB after adding a new disk sde:

pvcreate /dev/sde
vgextend myvg01 /dev/sde
lvextend -L +10G /dev/myvg01/mylv01
xfs_growfs /dev/myvg01/mylv01

8. Delete LVM components

When you need to delete a logical volume, how to operate?

Procedure:

Unmount the filesystem.

Remove logical volumes.

Remove the volume group.

Remove physical volumes.

umount /funlyp-lv01
lvremove /dev/myvg01/mylv01
vgremove myvg01
pvremove /dev/sdb /dev/sdc /dev/sde