How to Set Up LVM (Logical Volume Management) on Linux
A complete walkthrough from raw disks to a mounted, resizable logical volume — physical volumes, volume groups, and logical volumes explained as you build them.
LVM adds a flexible layer between raw disks and filesystems — letting you resize, add, or remove storage without the rigid constraints of working with partitions directly. This walks through the three-layer structure LVM is built from, from the ground up.
Step 1: install LVM tools
sudo apt install lvm2 # Debian/Ubuntu
sudo dnf install lvm2 # Fedora/RHELStep 2: create physical volumes from raw disks or partitions
sudo pvcreate /dev/sdb /dev/sdcA physical volume (PV) is LVM’s basic building block — a whole disk or a partition, marked for LVM to manage. This step doesn’t create any usable storage yet; it just registers these devices as available.
Step 3: verify the physical volumes
sudo pvs
sudo pvdisplayStep 4: combine physical volumes into a volume group
sudo vgcreate data-vg /dev/sdb /dev/sdcA volume group (VG) pools one or more physical volumes into a single space to allocate storage from — this is what makes it possible to later grow a logical volume beyond the size of any single physical disk, simply by adding another PV to the group.
Step 5: create a logical volume from the volume group
sudo lvcreate -L 100G -n mydata data-vgA logical volume (LV) is what actually gets formatted and mounted — think of it as a flexible, resizable “virtual partition” carved out of the volume group’s pooled space.
Step 6: format and mount the logical volume
sudo mkfs.ext4 /dev/data-vg/mydata
sudo mkdir /mnt/mydata
sudo mount /dev/data-vg/mydata /mnt/mydataStep 7: grow the logical volume later, without unmounting
sudo lvextend -L +50G /dev/data-vg/mydata
sudo resize2fs /dev/data-vg/mydataThis is LVM’s headline practical benefit: growing storage on a live, mounted filesystem, as long as the volume group has (or gains, via vgextend and another physical volume) enough free space to grow into.
Step 8: add more physical storage to the volume group later
sudo pvcreate /dev/sdd
sudo vgextend data-vg /dev/sddAdding a new disk to an existing volume group makes its space available for logical volumes to grow into — without needing to migrate data or reformat anything already in use.
Step 9: persist the mount across reboots
# /etc/fstab
/dev/data-vg/mydata /mnt/mydata ext4 defaults 0 2Why the three-layer structure is worth understanding, not just memorizing commands for
Physical volumes, volume groups, and logical volumes map directly onto the three problems LVM solves: PVs abstract away which physical disk storage actually lives on, VGs pool that storage into a single resizable space, and LVs carve out flexible, growable pieces of that pool for actual use. Understanding which layer a given command operates on — rather than treating pvcreate/vgcreate/lvcreate as an arbitrary sequence to memorize — makes it much easier to reason about what’s actually possible (growing an LV needs free space in its VG; growing a VG needs another PV) when planning storage changes later.