COS-lite-k8s docs - Set up microceph
Table of Contents
MicroCeph is a lightweight way of deploying a Ceph cluster with a focus on reduced ops that can be used with MicroK8s.
Single-node MicroCeph installation
Install MicroCeph
Install the most recent stable release of MicroCeph:
sudo snap install microceph
Next, as MicroCeph creator recommend, prevent the software from being auto-updated:
sudo snap refresh --hold microceph
Allowing the snap to be auto-updated can lead to unintended consequences. In enterprise environments especially, it is better to research the ramifications of software changes before those changes are implemented.
We need to bootstrap the Ceph cluster:
sudo microceph cluster bootstrap
At this point we can check the status of the cluster and query the list of available disks that should be empty. The disk status is queried with:
sudo microceph.ceph status
Its output should look like:
cluster:
id: 9539a8ee-825a-462a-94fa-15613c09cab1
health: HEALTH_WARN
mon charm-dev-juju-34 is low on available space
services:
mon: 1 daemons, quorum charm-dev-juju-34 (age 8s)
mgr: charm-dev-juju-34(active, since 3s)
osd: 0 osds: 0 up, 0 in
data:
pools: 0 pools, 0 pgs
objects: 0 objects, 0 B
usage: 0 B used, 0 B / 0 B avail
pgs:
Add storage
Three OSDs will be required to form a minimal Ceph cluster. In a production system, typically we would assign a physical block device to an OSD. However for this tutorial, we will make use of file backed OSDs for simplicity.
Add the three file-backed OSDs to the cluster by using the disk add command. In the example, three 4GiB files are being created:
sudo microceph disk add loop,4G,3
Connect MicroCeph to MicroK8s
Enable rook-ceph plugin by executing:
sudo microk8s enable rook-ceph
See more: rook-ceph addon
As we have already setup MicroCeph having it managed by rook is done with just:
sudo microk8s connect-external-ceph
At the end of this process you should have a storage class ready to use:
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
ceph-rbd rook-ceph.rbd.csi.ceph.com Delete Immediate true 1s
See also
References
Last updated 6 months ago.