A MAAS volume group is a storage configuration that utilizes Logical Volume Management (LVM) to provide flexible disk management. This setup allows administrators to create, resize, or delete logical volumes without being constrained by physical disk limitations.
LVM layout in MAAS
When deploying a machine with an LVM layout, MAAS performs the following steps:
- Partitioning the Boot Disk: The boot disk is divided into partitions, typically creating a small EFI partition (e.g., 512 MB) for boot purposes and allocating the remaining space as a physical volume for LVM.
- Creating a Volume Group: MAAS initializes a volume group (default name
vgroot) on the LVM physical volume. - Establishing Logical Volumes: Within this volume group, a logical volume (default name
lvroot) is created, formatted with a filesystem (commonly ext4), and mounted as the root filesystem (/).
Default partition scheme
| Name | Size | Type | Filesystem | Mount Point |
|---|---|---|---|---|
| sda | Disk | |||
| sda1 | 512 MB | Partition (EFI) | FAT32 | /boot/efi |
| sda2 | Remaining | Partition (LVM PV) | ||
| vgroot | sda2 size | Volume Group | ||
| lvroot | vgroot size | Logical Volume | ext4 | / |
Customizing LVM configuration
MAAS allows customization of the LVM setup through various parameters:
boot_size: Specifies the size of the boot partition. If set to 0, the/bootdirectory resides within the root filesystem.root_device: Designates the block device for the root partition, defaulting to the boot disk.root_size: Determines the size of the root partition. By default, it occupies 100% of the root device.vg_name: Sets the name of the volume group. The default isvgroot.
*lv_name: Assigns a name to the logical volume, withlvrootas the default.lv_size: Defines the size of the logical volume, defaulting to 100% of the volume group.
For more detailed information on MAAS storage configurations, refer to the MAAS storage reference.