LVM cheatsheet

Acronyms you must know

PV = Physical Volume
VG = Volume Group
LV = Logical Volume

    PV1  PV2   PV3  PV4
      \  |      |  /
       VG1      VG2
        |       |  \ 
       LV1     LV2  LV3

Step-by-Step LVM Setup

1. Add a Physical Disk

connect a physical/virtual disk to your system.

Overview of block devices

lsblk

Used/available space on mounted filesystems

df -h

2. Create Physical Volumes

Info

pvck        # Check PV metadata
pvdisplay   # Display PV attributes
pvs         # Report PV information
pvscan      # Scan for PVs

Create

pvcreate /dev/sda /dev/sdb /dev/sdc /dev/sdd

Delete

pvremove /dev/sdX

Edit

pvchange     # Change PV attributes
pvmove       # Move physical extents
pvresize     # Resize PV

3. Create Volume Groups

Info

vgck        # Check VG metadata
vgdisplay   # VG attributes
vgs         # Report VG info
vgscan      # Scan for VGs

Create

vgcreate vg0 /dev/sda

Delete

vgremove vg_name

Edit

vgcfgbackup   # Backs up volume group (VG) metadata
vgcfgrestore  # Restores VG metadata from backup
vgchange      # Change VG attributes
vgconvert     # Metadata format change
vgexport      # Exports a VG to make it unknown to the system
vgimport      # Imports a VG previously exported
vgimportclone # Imports and renames a VG to avoid conflicts
vgmerge       # Merges two VGs into one
vgsplit       # Splits a VG into two separate VGs
vgextend vg0 /dev/sdc /dev/sdd  # Adds physical volumes to a VG
vgreduce      # Removes physical volumes from a VG
vgrename      # Renames a VG
vgmknodes     # Recreates device nodes for LVM devices

4. Create Logical Volumes

Info

lvdisplay    # Show LV attributes
lvmdiskscan  # Scan for devices
lvs          # Report info
lvscan       # Scan for LVs

Create

lvcreate -n lvbackup -L 50G vgbackup -r

Delete

lvremove /dev/vg_name/lv_name

Edit

lvchange     # Change LV attributes
lvconvert    # Mirror/snapshot conversion
lvextend /dev/vg_name/lv_name
lvreduce     # Reduce size
lvresize     # Resize
lvrename     # Rename
resize2fs /dev/vg0/lv_root   # Resize filesystem
xfs_growfs -d /dev/vg-group-name/lv-name

5. Create a filesystem on your Logical Volume

mkfs.ext4 /dev/vgbackup/lvbackup

6. Mounting the Logical Volume

blkid /dev/vgbackup/lvbackup    # Get UUID
mkdir /path/to/folder           # Mount point
vim /etc/fstab                  # Add entry with UUID
mount -a                        # Mount all from fstab

Overview Commands

pvs     # List physical volumes
vgs     # List volume groups
lvs     # List logical volumes

pvdisplay
vgdisplay
lvdisplay

Snapshotting

lvcreate --size 1G --snapshot --name snap_name /dev/vg0/lvdata
lvconvert --merge /dev/vg0/snap_name

Filesystem Resize After LV Resize

lvextend -L +10G /dev/vgbackup/lvbackup
resize2fs /dev/vgbackup/lvbackup
xfs_growfs /path/to/your/mount/point

Helpful Tips

Always back up metadata:
```
vgcfgbackup
```
Reload partition tables without rebooting:
```
partprobe /dev/sdX
```