Requirements for creating or enlarging an LVM volume

Switch to root user
- ```
sudo -s
```
Install package parted (e.g. under Debian or Ubuntu)
- ```
apt get install parted
```
After adding or enlarging a hard disk while VM is running, the SCSI bus must be rescanned
- Scan for new hard disks
  - ```
  for i in /sys/class/scsi_host/*/scan; do echo "- - -">$i; done
```
- Scan for enlarged hard disks
  - ```
  for i in /sys/class/scsi_device/*/device/rescan; do echo 1>$i; done
```
To be able to use the additional hard disk space for LVM, a partition must first be created and initialized as PV (Physical Volume)
- (Optional) Initialization of the partition table with GPT - only for new hard disks (e.g. /dev/sdb)
  - ```
  parted /dev/sdb mktable gpt
```
- Create partition and initialize as PV
  - ```
  parted /dev/sdb unit mib mkpart primary 1 100%
```
- ```
parted /dev/sdb set 1 lvm on
```
  - ```
  partprobe
```
- ```
pvcreate /dev/sdb1
```
- Enlarge an existing partition and its PV (e.g. /dev/sdb1)
  - ```
  parted resizepart 1 100%
```
- ```
partprobe
```
  - ```
  pvresize /dev/sdb1
```

Create new LVM volume

Create VG (Volume Group) (e.g. "data")
- ```
vgcreate data /dev/sdb1
```
Create LV (Logical Volume) (e.g. "data01")
- ```
lvcreate -l +100%FREE -n data01 data
```
Create file system (e.g. EXT4)
- ```
mkfs.ext4 /dev/data/data01
```
Create mount point (e.g. /data)
- ```
mkdir /data
```

Edit /etc/fstab to automatically mount the LV

Add line:
/dev/data/data01 /data ext4 defaults 0 2

Extend an existing volume group with a volume

Enlarge existing LVM volume

Determine the name of the LV to be enlarged (e.g. /dev/data/data01)
- ```
lvdisplay
```
Enlarge LV
- ```
lvextend -l +100%FREE /dev/data/data01
```

Enlarge file system

BTRFS: btrfs filesystem resize max /data (/data = Mount point of LV /dev/data/data01)