Tech Tutorial: 363.2 Ceph Storage Clusters (weight: 8) #
Introduction #
Ceph is a highly resilient and scalable storage solution that allows enterprises to build and manage vast amounts of data in a distributed storage architecture. In this tutorial, we will explore how to set up and manage a basic Ceph storage cluster. We will cover some essential commands and configurations required for day-to-day management and troubleshooting of Ceph clusters.
Exam Objective: #
- Understand the architecture and deployment of Ceph storage clusters.
- Be able to perform basic Ceph cluster operations and maintenance.
Key Knowledge Areas: #
- Ceph cluster architecture
- Basic Ceph commands and usage
- Monitoring and maintaining a Ceph cluster
Utilities: #
- ceph
- rados
- rbd
- ceph-mon
- ceph-osd
Step-by-Step Guide #
Step 1: Understanding Ceph Components #
Ceph primarily consists of the following components:
- Ceph OSDs (Object Storage Daemons): Stores data as objects on storage nodes.
- Ceph Monitor (ceph-mon): Keeps a master copy of the cluster map.
- Ceph Manager (ceph-mgr): Provides additional monitoring and management.
- Ceph RADOS Block Device (RBD): Allows block-level storage access.
Step 2: Setting Up a Ceph Cluster #
Before beginning, ensure that you have at least three nodes to set up a minimal cluster.
- Install Ceph on all nodes:
sudo apt update
sudo apt install ceph-deploy
- Create a new cluster directory and cluster configuration:
mkdir my-ceph-cluster
cd my-ceph-cluster
ceph-deploy new node1 node2 node3
- Install Ceph on all nodes:
ceph-deploy install node1 node2 node3
- Deploy the initial monitor(s) and gather the keys:
ceph-deploy mon create-initial
Step 3: Adding OSDs #
OSDs are the heart of the Ceph storage, handling the storage of data in terms of objects.
ceph-deploy osd create --data /dev/sdb node1
Replace /dev/sdb
with your storage drive identifier.
Step 4: Basic Ceph Commands #
- Check cluster health:
ceph health
- List all OSDs:
ceph osd ls
- Get cluster status:
ceph -s
Step 5: Using RADOS and RBD Utilities #
- Create a pool with RADOS:
ceph osd pool create mypool 128 128
- List all pools:
rados lspools
- Create an RBD (block device):
rbd create mypool/myvolume --size 1024
- Map the RBD block device:
rbd map mypool/myvolume
Step 6: Monitoring and Maintaining #
- Monitor cluster utilization:
ceph df
- Check OSD status:
ceph osd stat
- Repairing OSDs:
ceph osd repair osd.<osd-id>
Replace <osd-id>
with the actual OSD ID.
Conclusion #
In this tutorial, we’ve gone through the basics of setting up and managing a Ceph storage cluster. The commands and procedures outlined provide a foundation for further exploration and management of more complex Ceph functionalities. Ceph’s scalable and resilient nature makes it an ideal solution for large-scale storage requirements in modern data centers.