Ceph
PLEASE NOTE: This document applies to v0.7 version and not to the latest stable release v1.8
Documentation for other releases can be found by using the version selector in the top right of any doc page.Quickstart Guide
Welcome to Rook! We hope you have a great experience installing the Rook storage platform to enable highly available, durable storage in your cluster. If you have any questions along the way, please don’t hesitate to ask us in our Slack channel.
This guide will walk you through the basic setup of a Rook cluster. This will enable you to consume block, object, and file storage from other pods running in your cluster.
Minimum Version
Kubernetes v1.6 or higher is targeted by Rook (while Rook is in alpha it will track the latest release to use the latest features).
Support is available for Kubernetes v1.5.2, although your mileage may vary. You will need to use the yaml files from the 1.5 folder.
Prerequisites
To make sure you have a Kubernetes cluster that is ready for Rook
, you can follow these instructions.
If you are using dataDirHostPath
to persist rook data on kubernetes hosts, make sure your host has at least 5GB of space available on the specified path.
TL;DR
If you’re feeling lucky, a simple Rook cluster can be created with the following kubectl commands. For the more detailed install, skip to the next section to deploy the Rook operator.
cd cluster/examples/kubernetes
kubectl create -f rook-operator.yaml
kubectl create -f rook-cluster.yaml
After the cluster is running, you can create block, object, or file storage to be consumed by other applications in your cluster.
Deploy the Rook Operator
The first step is to deploy the Rook system components, which include the Rook agent running on each node in your cluster as well as Rook operator pod.
cd cluster/examples/kubernetes
kubectl create -f rook-operator.yaml
# verify the rook-operator and rook-agents pods are in the `Running` state before proceeding
kubectl -n rook-system get pod
You can also deploy the operator with the Rook Helm Chart.
Restart Kubelet
(K8S 1.7.x and older only)
For versions of Kubernetes prior to 1.8, the Kubelet process on all nodes will require a restart after the Rook operator and Rook agents have been deployed. As part of their initial setup, the Rook agents deploy and configure a Flexvolume plugin in order to integrate with Kubernetes’ volume controller framework. In Kubernetes v1.8+, the dynamic Flexvolume plugin discovery will find and initialize our plugin, but in older versions of Kubernetes a manual restart of the Kubelet will be required.
Disable Attacher-detacher controller
(K8S 1.6.x only)
For Kubernetes 1.6, it is also necessary to pass the --enable-controller-attach-detach=false
flag to Kubelet when you restart it. This is a workaround for a Kubernetes issue that only affects 1.6.
Create a Rook Cluster
Now that the Rook operator and agent pods are running, we can create the Rook cluster. For the cluster to survive reboots,
make sure you set the dataDirHostPath
property. For more settings, see the documentation on configuring the cluster.
Save the cluster spec as rook-cluster.yaml
:
apiVersion: v1
kind: Namespace
metadata:
name: rook
---
apiVersion: rook.io/v1alpha1
kind: Cluster
metadata:
name: rook
namespace: rook
spec:
dataDirHostPath: /var/lib/rook
storage:
useAllNodes: true
useAllDevices: false
storeConfig:
storeType: bluestore
databaseSizeMB: 1024
journalSizeMB: 1024
Create the cluster:
kubectl create -f rook-cluster.yaml
Use kubectl
to list pods in the rook
namespace. You should be able to see the following pods once they are all running:
$ kubectl -n rook get pod
NAME READY STATUS RESTARTS AGE
rook-api-1511082791-7qs0m 1/1 Running 0 5m
rook-ceph-mgr0-1279756402-wc4vt 1/1 Running 0 5m
rook-ceph-mon0-jflt5 1/1 Running 0 6m
rook-ceph-mon1-wkc8p 1/1 Running 0 6m
rook-ceph-mon2-p31dj 1/1 Running 0 6m
rook-ceph-osd-0h6nb 1/1 Running 0 5m
Storage
For a walkthrough of the three types of storage exposed by Rook, see the guides for:
- Block: Create block storage to be consumed by a pod
- Object: Create an object store that is accessible inside or outside the Kubernetes cluster
- Shared File System: Create a file system to be shared across multiple pods
Tools
We have created a toolbox container that contains the full suite of Ceph clients for debugging and troubleshooting your Rook cluster. Please see the toolbox readme for setup and usage information. Also see our advanced configuration document for helpful maintenance and tuning examples.
The toolbox also contains the rookctl
tool as required in the File System and Object walkthroughs, or a simplified walkthrough of block, file and object storage. In the near future, rookctl
will not be required for kubernetes scenarios.
Monitoring
Each Rook cluster has some built in metrics collectors/exporters for monitoring with Prometheus. To learn how to set up monitoring for your Rook cluster, you can follow the steps in the monitoring guide.
Teardown
When you are done with the test cluster, see these instructions to clean up the cluster.