Create an mdadm software RAID level 1 (raid1)¶
Caution
This feature is available as Technology Preview. Use such configuration for testing and evaluation purposes only. For the Technology Preview feature definition, refer to Technology Preview features.
Warning
The EFI system partition partflags: ['esp']
must be
a physical partition in the main partition table of the disk, not under
LVM or mdadm software RAID.
During configuration of your custom bare metal host profile as described in
Create a custom bare metal host profile, you can create an mdadm-based software RAID
device raid1
by describing the mdadm devices under the softRaidDevices
field in BaremetalHostProfile
. For example:
...
softRaidDevices:
- name: /dev/md0
devices:
- partition: sda1
- partition: sdb1
- name: raid-name
devices:
- partition: sda2
- partition: sdb2
...
The only two required fields to describe RAID devices are name
and devices
. The devices
field must describe at least two partitions
to build an mdadm RAID on it. For the mdadm RAID parameters, see
API: BareMetalHostProfile spec.
Caution
The mdadm RAID devices cannot be created on top of LVM devices, as well as LVM devices cannot be created on top of mdadm devices.
The following example illustrates an extract of BaremetalHostProfile
with /
on the mdadm raid1
and some data storage on raid0
:
...
devices:
- device:
byPath: /dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:1
wipe: true
partitions:
- name: root_part1
sizeGiB: 120
- name: rest_sda
sizeGiB: 0
- device:
byPath: /dev/disk/by-path/pci-0000:00:05.0-scsi-0:0:0:2
wipe: true
partitions:
- name: root_part2
sizeGiB: 120
- name: rest_sdb
sizeGiB: 0
softRaidDevices:
- name: root
level: raid1 ## <-- mdadm raid1
devices:
- partition: root_part1
- partition: root_part2
- name: raid-name
level: raid0 ## <-- mdadm raid0
devices:
- partition: rest_sda
- partition: rest_sdb
fileSystems:
- fileSystem: ext4
softRaidDevice: root
mountPoint: /
mountOpts: "noatime,nodiratime"
- fileSystem: ext4
softRaidDevice: data
mountPoint: /mnt/data
...
Warning
Any data stored on any device defined in the fileSystems
list can be deleted or corrupted during cluster (re)deployment. It happens
because each device from the fileSystems
list is a part of the
rootfs
directory tree that is overwritten during (re)deployment.
Examples of affected devices include:
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 (deprecated) or wipeDevice
structure (recommended
since Container Cloud 2.26.0) have no effect in this case and cannot
protect data on these devices.
Therefore, to prevent data loss, move the necessary data from these file systems to another server beforehand, if required.