Default configuration of the host system storage

The default host profile requires three storage devices in the following strict order:

1. Boot device and operating system storage

   This device contains boot data and operating system data. It is partitioned using the GUID Partition Table (GPT) labels. The root file system is an ext4 file system created on top of an LVM logical volume. For a detailed layout, refer to the table below.

2. Local volumes device

   This device contains an ext4 file system with directories mounted as persistent volumes to Kubernetes. These volumes are used by the MOSK services to store its data, including monitoring and identity databases.

3. Ceph storage device

   This device is used as a Ceph datastore or Ceph OSD on MOSK clusters.

The following table summarizes the default configuration of the host system storage set up by MOSK bare-metal management.

Default configuration of the bare-metal host storage

Device/partition	Name/Mount point	Recommended size, GB	Description
/dev/sda1	bios_grub	4 MiB	The mandatory GRUB boot partition required for non-UEFI systems.
/dev/sda2	UEFI -> /boot/efi	0.2 GiB	The boot partition required for the UEFI boot mode.
/dev/sda3	config-2	64 MiB	The mandatory partition for the cloud-init configuration. Used during the first host boot for initial configuration.
/dev/sda4	lvm_root_part	100% of the remaining free space in the LVM volume group	The main LVM physical volume that is used to create the root file system.
/dev/sdb	lvm_lvp_part -> /mnt/local-volumes	100% of the remaining free space in the LVM volume group	The LVM physical volume that is used to create the file system for LocalVolumeProvisioner.
/dev/sdc	-	100% of the remaining free space in the LVM volume group	Clean raw disk that will be used for the Ceph storage backend on MOSK clusters.

If required, you can customize the default host storage configuration. For details, see Create MOSK host profiles.