Ceph Upgrades

This guide will walk through the steps to upgrade the version of Ceph in a Rook cluster. Rook and Ceph upgrades are designed to ensure data remains available even while the upgrade is proceeding. Rook will perform the upgrades in a rolling fashion such that application pods are not disrupted.

Rook is cautious when performing upgrades. When an upgrade is requested (the Ceph image has been updated in the CR), Rook will go through all the daemons one by one and will individually perform checks on them. It will make sure a particular daemon can be stopped before performing the upgrade. Once the deployment has been updated, it checks if this is ok to continue. After each daemon is updated we wait for things to settle (monitors to be in a quorum, PGs to be clean for OSDs, up for MDSes, etc.), then only when the condition is met we move to the next daemon. We repeat this process until all the daemons have been updated.

Considerations¶

• WARNING: Upgrading a Rook cluster is not without risk. There may be unexpected issues or obstacles that damage the integrity and health of the storage cluster, including data loss.
• The Rook cluster's storage may be unavailable for short periods during the upgrade process.
• Read this document in full before undertaking a Rook cluster upgrade.

Supported Versions¶

Rook v1.16 supports the following Ceph versions:

• Ceph Squid v19.2.0 or newer
• Ceph Reef v18.2.0 or newer

Ceph Images¶

Official Ceph container images can be found on Quay.

These images are tagged in a few ways:

• The most explicit form of tags are full-ceph-version-and-build tags (e.g., v18.2.4-20240724). These tags are recommended for production clusters, as there is no possibility for the cluster to be heterogeneous with respect to the version of Ceph running in containers.
• Ceph major version tags (e.g., v18) are useful for development and test clusters so that the latest version of Ceph is always available.

Ceph containers other than the official images from the registry above will not be supported.

Example Upgrade to Ceph Reef¶

1. Update the Ceph daemons¶

The upgrade will be automated by the Rook operator after the desired Ceph image is changed in the CephCluster CRD (spec.cephVersion.image).

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ROOK_CLUSTER_NAMESPACE=rook-ceph
NEW_CEPH_IMAGE='quay.io/ceph/ceph:v18.2.4-20240724'
kubectl -n $ROOK_CLUSTER_NAMESPACE patch CephCluster $ROOK_CLUSTER_NAMESPACE --type=merge -p "{\"spec\": {\"cephVersion\": {\"image\": \"$NEW_CEPH_IMAGE\"}}}"

2. Update the toolbox image¶

Since the Rook toolbox is not controlled by the Rook operator, users must perform a manual upgrade by modifying the image to match the ceph version employed by the new Rook operator release. Employing an outdated Ceph version within the toolbox may result in unexpected behaviour.

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kubectl -n rook-ceph set image deploy/rook-ceph-tools rook-ceph-tools=quay.io/ceph/ceph:v18.2.4-20240724

3. Wait for the pod updates¶

As with upgrading Rook, now wait for the upgrade to complete. Status can be determined in a similar way to the Rook upgrade as well.

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watch --exec kubectl -n $ROOK_CLUSTER_NAMESPACE get deployments -l rook_cluster=$ROOK_CLUSTER_NAMESPACE -o jsonpath='{range .items[*]}{.metadata.name}{"  \treq/upd/avl: "}{.spec.replicas}{"/"}{.status.updatedReplicas}{"/"}{.status.readyReplicas}{"  \tceph-version="}{.metadata.labels.ceph-version}{"\n"}{end}'

Confirm the upgrade is completed when the versions are all on the desired Ceph version.

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kubectl -n $ROOK_CLUSTER_NAMESPACE get deployment -l rook_cluster=$ROOK_CLUSTER_NAMESPACE -o jsonpath='{range .items[*]}{"ceph-version="}{.metadata.labels.ceph-version}{"\n"}{end}' | sort | uniq
This cluster is not yet finished:
    ceph-version=v17.2.7-0
    ceph-version=v18.2.4-0
This cluster is finished:
    ceph-version=v18.2.4-0

4. Verify cluster health¶

Verify the Ceph cluster's health using the health verification.