lvm

Linux Logical Volume Manager.

• Tutorial
• Overview
• Managing

General flow

Physical volumes (pv) are grouped into volume groups (vg). Volume groups are sliced up into logical volumes (lv). Because of that, the general flow is something like:

## Partitioning is not necessary, so no need for fdisk or sgdisk
pvcreate /dev/sd{x..z}
vgcreate vg_scratch /dev/sd{x..z}
lvcreate -l 95%FREE -n lv_scratch vg_scratch
mkfs.ext4 /dev/vg_scratch/lv_scratch

Examples

Show a bunch of info

pvdisplay -v
pvs -v
pvs -a
pvs --segments
vgdisplay -v
vgs -v
vgs -a -o +devices

Show system disks and if they are in an LVM

lvmdiskscan

Show all logical volumes

lvs

Activate all volume groups

vgchange -a y

Create a physical volume

physical volumes are groups of physical disks that can be used to create logical volumes

pvcreate pv_name /dev/sdb2 /dev/sdc2

Create a logical volume

This creates a specifically named logical volume on a volume group named vg_data

lvcreate -L 10G -n lv_name vg_data

Show how each logical volume is set up

lvdisplay

Show free extents

vgs -o vg_free_count

Extend a volume group to 1TB

lvextend -L 1T /dev/vgroot/lv_srv && \
resize2fs /dev/mapper/vgroot-lv_srv && \
df -h /srv

Extend a volume group to its max

lvextend -l +100%FREE /dev/vgroot/lv_srv && \
resize2fs /dev/mapper/vgroot-lv_srv && \
df -h /srv