LVM
also: Logical Volume Manager
Logical Volume Manager (LVM) is a storage abstraction layer that allows you to create flexible virtual disk partitions called logical volumes from physical storage devices, enabling dynamic resizing and management without rebooting.
LVM sits between your physical hard drives and the filesystems, providing a layer of indirection that decouples storage allocation from the underlying hardware. Instead of partitioning disks directly, you group physical volumes (PVs) into volume groups (VGs), then carve logical volumes (LVs) from those groups.
This architecture enables powerful features: you can resize logical volumes on-the-fly, span a single volume across multiple disks, create snapshots for backups, and manage storage without downtime. For example, if your /home partition is running out of space, you can simply extend the logical volume backing it rather than repartitioning.
A typical LVM setup looks like: physical disk /dev/sda → physical volume pv0 → volume group vg0 → logical volumes lv_root, lv_home, lv_swap → mounted as /, /home, swap space.