Mateusz Gozdek
8ba3762fa4
Found by running the following command: codespell -S .git,*.png,*.jpg -L \ aks,keyserver,atleast,dne,ser,ist,files\',ba,dum,iam,te -f -H Signed-off-by: Mateusz Gozdek <mgozdekof@gmail.com>
65 lines
2.6 KiB
Markdown
65 lines
2.6 KiB
Markdown
---
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title: Ceph CSI
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weight: 3200
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indent: true
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---
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# Ceph CSI Drivers
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There are two CSI drivers integrated with Rook that will enable different scenarios:
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* RBD: This driver is optimized for RWO pod access where only one pod may access the storage
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* CephFS: This driver allows for RWX with one or more pods accessing the same storage
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The drivers are enabled automatically with the Rook operator. They will be started
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in the same namespace as the operator when the first CephCluster CR is created.
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For documentation on consuming the storage:
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* RBD: See the [Block Storage](ceph-block.md) topic
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* CephFS: See the [Shared Filesystem](ceph-filesystem.md) topic
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## Configure CSI Drivers in non-default namespace
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If you've deployed the Rook operator in a namespace other than "rook-ceph",
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change the prefix in the provisioner to match the namespace you used. For
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example, if the Rook operator is running in the namespace "my-namespace" the
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provisioner value should be "my-namespace.rbd.csi.ceph.com". The same provisioner
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name needs to be set in both the storageclass and snapshotclass.
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## Liveness Sidecar
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All CSI pods are deployed with a sidecar container that provides a prometheus metric for tracking if the CSI plugin is alive and running.
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These metrics are meant to be collected by prometheus but can be accesses through a GET request to a specific node ip.
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for example `curl -X get http://[pod ip]:[liveness-port][liveness-path] 2>/dev/null | grep csi`
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the expected output should be
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```console
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$ curl -X GET http://10.109.65.142:9080/metrics 2>/dev/null | grep csi
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# HELP csi_liveness Liveness Probe
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# TYPE csi_liveness gauge
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csi_liveness 1
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```
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Check the [monitoring doc](ceph-monitoring.md) to see how to integrate CSI
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liveness and grpc metrics into ceph monitoring.
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## Dynamically Expand Volume
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### Prerequisite
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* For filesystem resize to be supported for your Kubernetes cluster, the
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kubernetes version running in your cluster should be >= v1.15 and for block
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volume resize support the Kubernetes version should be >= v1.16. Also,
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`ExpandCSIVolumes` feature gate has to be enabled for the volume resize
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functionality to work.
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To expand the PVC the controlling StorageClass must have `allowVolumeExpansion`
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set to `true`. `csi.storage.k8s.io/controller-expand-secret-name` and
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`csi.storage.k8s.io/controller-expand-secret-namespace` values set in
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storageclass. Now expand the PVC by editing the PVC
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`pvc.spec.resource.requests.storage` to a higher values than the current size.
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Once PVC is expanded on backend and same is reflected size is reflected on
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application mountpoint, the status capacity `pvc.status.capacity.storage` of
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PVC will be updated to new size.
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