Editing Tutorials:Monitoring with Tensorboard on the GPU cluster (section)

=== Local persistent volumes for Tensorboard logging ===

The following obtains a persistent volume claim for a local PV for data storage, as well as a PV for Tensorboard logging. Note that both can be done with a single config file. Code examples can be found in the subdirectory "example_2" of the tutorial sample code, [[File:Kubernetes_samples.zip|Kubernetes samples]]. As a first step, run the docker-compose and push the resulting container to the CCU registry,

<syntaxhighlight lang="bash">
> docker-compose up --build
[Wait a bit until the program has started, then ^C]
> docker push ccu.uni-konstanz.de:5000/your.username/tf-mnist-tb:0.1
</syntaxhighlight>

Also, create the Kubernetes scripts as before in the kubernetes subdirectory. Then, check out "pvc.yaml".

<syntaxhighlight lang="yaml">
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  # the name of the PVC, we refer to this in the container configuration
  name: your-username-tf-mnist-pvc

spec:
  resources:
    requests:
      # storage resource request. This PVC can only be bound to volumes which
      # have at least 8 GiB of storage available.
      storage: 8Gi

  # the requested storage class here is fast data storage.
  storageClassName: local-ssd

  # leave these unchanged, they must match the PV type, otherwise binding will fail
  accessModes:
    - ReadWriteOnce
  volumeMode: Filesystem
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  # the second claim is for tensorboard logging, it needs its own ID.
  name: your-username-tf-mnist-tb-pvc

spec:
  resources:
    requests:
      # Tensorboard logging typically requires not that much storage.
      storage: 2Gi

  # this storage class is parsed by the local Tensorboard instance
  # exposed to the network at port 6116.
  storageClassName: local-tensorboard

  # leave these unchanged, they must match the PV type, otherwise binding will fail
  accessModes:
    - ReadWriteOnce
  volumeMode: Filesystem
</syntaxhighlight>

Note that all names were prepended with your username to make them unique. When the claim is defined to your satisfaction, apply it like this:

<syntaxhighlight lang="yaml">
> kubectl apply -f pvc.yml
</syntaxhighlight>

You can again check on the status of this (and every other) claim:

<syntaxhighlight lang="yaml">
> kubectl get pvc
NAME                            STATUS    VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS        AGE
your-username-tf-mnist-pvc      Pending                                      local-ssd           11s
your-username-tf-mnist-tb-pvc   Pending                                      local-tensorboard   11s
</syntaxhighlight>

Since the claim has not been used by a container yet, it is not yet bound to a persitent volume (PV). The contents of the PV can be accessed like any other PV, see previous tutorial.