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content/en/docs/tasks/manage-daemon/update-daemon-set.md

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+---
+reviewers:
+- janetkuo
+title: Perform a Rolling Update on a DaemonSet
+content_template: templates/task
+---
+
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+This page shows how to perform a rolling update on a DaemonSet. 
+
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+* The DaemonSet rolling update feature is only supported in Kubernetes version 1.6 or later.
+
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+## DaemonSet Update Strategy
+
+DaemonSet has two update strategy types:
+
+* OnDelete: This is the default update strategy for backward-compatibility. With
+  `OnDelete` update strategy, after you update a DaemonSet template, new
+  DaemonSet pods will *only* be created when you manually delete old DaemonSet
+  pods. This is the same behavior of DaemonSet in Kubernetes version 1.5 or
+  before.
+* RollingUpdate: With `RollingUpdate` update strategy, after you update a
+  DaemonSet template, old DaemonSet pods will be killed, and new DaemonSet pods
+  will be created automatically, in a controlled fashion. 
+
+## Caveat: Updating DaemonSet created from Kubernetes version 1.5 or before 
+
+If you try a rolling update on a DaemonSet that was created from Kubernetes
+version 1.5 or before, a rollout will be triggered when you *first* change the
+DaemonSet update strategy to `RollingUpdate`, no matter if DaemonSet template is
+modified or not. If the DaemonSet template is not changed, all existing DaemonSet
+pods will be restarted (deleted and created).
+
+Therefore, make sure you want to trigger a rollout before you first switch the
+strategy to `RollingUpdate`.
+
+## Performing a Rolling Update
+
+To enable the rolling update feature of a DaemonSet, you must set its
+`.spec.updateStrategy.type` to `RollingUpdate`. 
+
+You may want to set `.spec.updateStrategy.rollingUpdate.maxUnavailable` (default
+to 1) and `.spec.minReadySeconds` (default to 0) as well.
+
+
+### Step 1: Checking DaemonSet `RollingUpdate` update strategy
+
+First, check the update strategy of your DaemonSet, and make sure it's set to 
+`RollingUpdate`:
+
+```shell
+kubectl get ds/<daemonset-name> -o go-template='{{.spec.updateStrategy.type}}{{"\n"}}'
+``` 
+
+If you haven't created the DaemonSet in the system, check your DaemonSet
+manifest with the following command instead:
+
+```shell
+kubectl create -f ds.yaml --dry-run -o go-template='{{.spec.updateStrategy.type}}{{"\n"}}'
+``` 
+
+The output from both commands should be:
+
+```shell
+RollingUpdate
+```
+
+If the output isn't `RollingUpdate`, go back and modify the DaemonSet object or
+manifest accordingly.
+
+### Step 2: Creating a DaemonSet with `RollingUpdate` update strategy
+
+If you have already created the DaemonSet, you may skip this step and jump to
+step 3.
+
+After verifying the update strategy of the DaemonSet manifest, create the DaemonSet:
+
+```shell
+kubectl create -f ds.yaml
+```
+
+Alternatively, use `kubectl apply` to create the same DaemonSet if you plan to
+update the DaemonSet with `kubectl apply`. 
+
+```shell
+kubectl apply -f ds.yaml
+```
+
+### Step 3: Updating a DaemonSet template 
+
+Any updates to a `RollingUpdate` DaemonSet `.spec.template` will trigger a rolling
+update. This can be done with several different `kubectl` commands.
+
+#### Declarative commands
+
+If you update DaemonSets using
+[configuration files](/docs/concepts/overview/object-management-kubectl/declarative-config/),
+use `kubectl apply`:
+
+```shell
+kubectl apply -f ds-v2.yaml
+```
+
+#### Imperative commands
+
+If you update DaemonSets using
+[imperative commands](/docs/concepts/overview/object-management-kubectl/imperative-command/),
+use `kubectl edit` or `kubectl patch`:
+
+```shell
+kubectl edit ds/<daemonset-name>
+```
+
+```shell
+kubectl patch ds/<daemonset-name> -p=<strategic-merge-patch>
+```
+
+##### Updating only the container image 
+
+If you just need to update the container image in the DaemonSet template, i.e.
+`.spec.template.spec.containers[*].image`, use `kubectl set image`:
+
+```shell
+kubectl set image ds/<daemonset-name> <container-name>=<container-new-image>
+```
+
+### Step 4: Watching the rolling update status
+
+Finally, watch the rollout status of the latest DaemonSet rolling update:
+
+```shell 
+kubectl rollout status ds/<daemonset-name> 
+```
+
+When the rollout is complete, the output is similar to this:
+
+```shell
+daemonset "<daemonset-name>" successfully rolled out
+```
+
+## Troubleshooting 
+
+### DaemonSet rolling update is stuck
+
+Sometimes, a DaemonSet rolling update may be stuck. Here are some possible
+causes:
+
+#### Some nodes run out of resources
+
+The rollout is stuck because new DaemonSet pods can't be scheduled on at least one
+node. This is possible when the node is 
+[running out of resources](/docs/tasks/administer-cluster/out-of-resource/).
+
+When this happens, find the nodes that don't have the DaemonSet pods scheduled on
+by comparing the output of `kubectl get nodes` and the output of:
+
+```shell
+kubectl get pods -l <daemonset-selector-key>=<daemonset-selector-value> -o wide 
+```
+
+Once you've found those nodes, delete some non-DaemonSet pods from the node to
+make room for new DaemonSet pods. Note that this will cause service disruption 
+if the deleted pods are not controlled by any controllers, or if the pods aren't
+replicated. This doesn't respect 
+[PodDisruptionBudget](/docs/tasks/configure-pod-container/configure-pod-disruption-budget/)
+either.
+
+#### Broken rollout
+
+If the recent DaemonSet template update is broken, for example, the container is
+crash looping, or the container image doesn't exist (often due to a typo),
+DaemonSet rollout won't progress. 
+
+To fix this, just update the DaemonSet template again. New rollout won't be
+blocked by previous unhealthy rollouts. 
+
+#### Clock skew
+
+If `.spec.minReadySeconds` is specified in the DaemonSet, clock skew between 
+master and nodes will make DaemonSet unable to detect the right rollout
+progress. 
+
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+* See [Task: Performing a rollback on a
+  DaemonSet](/docs/tasks/manage-daemon/rollback-daemon-set/)
+* See [Concepts: Creating a DaemonSet to adopt existing DaemonSet pods](/docs/concepts/workloads/controllers/daemonset/)
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