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 Mirantis Container Cloud 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 managed clusters. It is used as a Ceph datastore or Ceph OSD.

    Before Container Cloud 2.20.0, this device is also required as the third device for management or regional clusters.

    Ceph changes in Container Cloud 2.20

    • Since Container Cloud 2.20.0, the Ceph cluster does not deploy on management and regional clusters to reduce resource consumption.

    • Ceph cluster is automatically removed from existing management and regional clusters during the Container Cloud update to 2.20.0.

    • Managed clusters continue using Ceph as a distributed storage system.

Warning

All data will be wiped during cluster deployment on devices defined directly or indirectly in the fileSystems list of BareMetalHostProfile. For example:

  • A raw device partition with a file system on it

  • A device partition in a volume group with a logical volume that has a file system on it

  • An mdadm RAID device with a file system on it

  • An LVM RAID device with a file system on it

The wipe field is always considered true for these devices. The false value is ignored.

Therefore, to prevent data loss, move the necessary data from these file systems to another server beforehand, if required.

The following table summarizes the default configuration of the host system storage set up by the Container Cloud 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 is used for the Ceph storage back end on managed clusters.

Before Container Cloud 2.20.0, this disk is also required for management or regional clusters.

Ceph changes in Container Cloud 2.20

  • Since Container Cloud 2.20.0, the Ceph cluster does not deploy on management and regional clusters to reduce resource consumption.

  • Ceph cluster is automatically removed from existing management and regional clusters during the Container Cloud update to 2.20.0.

  • Managed clusters continue using Ceph as a distributed storage system.

If required, you can customize the default host storage configuration. For details, see Create a custom host profile.