How to Set Up a Ceph Cluster on a Single Node

For lab or testing purposes, it’s possible to deploy a Ceph cluster on a single machine.

We can integrate it with Proxmox VE as Storage backend

System requirement:

– 4 disk (1 disk for OS and 3 for OSDs)
– Operating System Rocky Linux 9
– The IP address used in this article is: 192.168.1.31

# System Preparation

– Configure /etc/hosts

127.0.0.1   localhost 
192.168.1.31	ceph-singlenode.imanudin.web.id    ceph-singlenode

– Configure Hostname

hostnamectl set-hostname ceph-singlenode.imanudin.web.id

– Disable Firewall

sed -i s/'SELINUX='/'#SELINUX='/g /etc/selinux/config
echo 'SELINUX=disabled' >> /etc/selinux/config
setenforce 0
service firewalld stop
service iptables stop
service ip6tables stop
systemctl disable firewalld
systemctl disable iptables
systemctl disable ip6tables

# Install Dependencies

dnf install podman python3 lvm2

# Install cephadm

CEPH_RELEASE=19.2.1
curl --silent --remote-name --location https://download.ceph.com/rpm-${CEPH_RELEASE}/el9/noarch/cephadm
chmod +x cephadm

Note: For the latest version (CEPH_RELEASE), you can check here: https://docs.ceph.com/en/latest/releases/#active-releases

# Add repo ceph squid

./cephadm add-repo --release squid
./cephadm install
cephadm install ceph-common

For the latest and stable version (CEPH_RELEASE), you can check here: : https://docs.ceph.com/en/latest/releases/#active-releases

# Boostrap ceph

cephadm bootstrap \
--cluster-network 192.168.1.0/24 \
--mon-ip 192.168.1.31 \
--dashboard-password-noupdate \
--initial-dashboard-user admin \
--initial-dashboard-password ceph \
--allow-fqdn-hostname \
--single-host-defaults

Below is an example of the process.

Fetching dashboard port number...
Ceph Dashboard is now available at:

             URL: https://ceph-singlenode.imanudin.web.id:8443/
            User: admin
        Password: ceph

Enabling client.admin keyring and conf on hosts with "admin" label
Saving cluster configuration to /var/lib/ceph/e8e018b8-0fd2-11f0-bcca-bc2411e54572/config directory
You can access the Ceph CLI as following in case of multi-cluster or non-default config:

        sudo /usr/sbin/cephadm shell --fsid e8e018b8-0fd2-11f0-bcca-bc2411e54572 -c /etc/ceph/ceph.conf -k /etc/ceph/ceph.client.admin.keyring

Or, if you are only running a single cluster on this host:

        sudo /usr/sbin/cephadm shell 

Bootstrap complete.

# Setup OSDs

Make the 3 available disks as OSDs.

ceph orch apply osd --all-available-devices

Check the status using the ceph -s or ceph -w command, and ensure health is HEALTH_OK

# Perform a login test on the dashboard.

Use admin as the username and ceph as the password to log in to the Ceph dashboard, based on the bootstrap process above.

# Test create pool

ceph osd pool create rbdpool
ceph osd pool application enable rbdpool rbd

The above command will create a pool named rbdpool, with the application type set to rbd.

# Test create RADOS Block Device

rbd create -p rbdpool vm-100 --size 30G
rbd create -p rbdpool vm-200 --size 50G
rbd list -p rbdpool
rbd info -p rbdpool vm-100

[root@ceph-singlenode ~]# rbd info -p rbdpool vm-100
rbd image 'vm-100':
        size 30 GiB in 7680 objects
        order 22 (4 MiB objects)
        snapshot_count: 0
        id: 37e1c5dad18a
        block_name_prefix: rbd_data.37e1c5dad18a
        format: 2
        features: layering, exclusive-lock, object-map, fast-diff, deep-flatten
        op_features: 
        flags: 
        create_timestamp: Wed Apr  2 22:13:28 2025
        access_timestamp: Wed Apr  2 22:13:28 2025
        modify_timestamp: Wed Apr  2 22:13:28 2025

Congratulations, you have successfully created a Ceph cluster with a single node (single machine). This Ceph cluster can be used for testing integration with Proxmox VE or other platforms.

Good Luck 🙂