Chapter 5. Using quotas and limit ranges

Procedure

1. To determine how many GPUs are available on a node in your cluster, use the following command:

   $ oc describe node ip-172-31-27-209.us-west-2.compute.internal | egrep 'Capacity|Allocatable|gpu'

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   Example output

   openshift.com/gpu-accelerator=true
   Capacity:
    nvidia.com/gpu:  2
   Allocatable:
    nvidia.com/gpu:  2
    nvidia.com/gpu:  0           0

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   In this example, 2 GPUs are available.

2. Use this command to set a quota in the namespace nvidia. In this example, the quota is 1:

   $ cat gpu-quota.yaml

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   Example output

   apiVersion: v1
   kind: ResourceQuota
   metadata:
     name: gpu-quota
     namespace: nvidia
   spec:
     hard:
       requests.nvidia.com/gpu: 1

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3. Create the quota with the following command:

   $ oc create -f gpu-quota.yaml

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   Example output

   resourcequota/gpu-quota created

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4. Verify that the namespace has the correct quota set using the following command:

   $ oc describe quota gpu-quota -n nvidia

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   Example output

   Name:                    gpu-quota
   Namespace:               nvidia
   Resource                 Used  Hard
   --------                 ----  ----
   requests.nvidia.com/gpu  0     1

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5. Run a pod that asks for a single GPU with the following command:

   $ oc create pod gpu-pod.yaml

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   Example output

   apiVersion: v1
   kind: Pod
   metadata:
     generateName: gpu-pod-s46h7
     namespace: nvidia
   spec:
     restartPolicy: OnFailure
     containers:
     - name: rhel7-gpu-pod
       image: rhel7
       env:
         - name: NVIDIA_VISIBLE_DEVICES
           value: all
         - name: NVIDIA_DRIVER_CAPABILITIES
           value: "compute,utility"
         - name: NVIDIA_REQUIRE_CUDA
           value: "cuda>=5.0"
   
       command: ["sleep"]
       args: ["infinity"]
   
       resources:
         limits:
           nvidia.com/gpu: 1

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6. Verify that the pod is running with the following command:

   $ oc get pods

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   Example output

   NAME              READY     STATUS      RESTARTS   AGE
   gpu-pod-s46h7     1/1       Running     0          1m

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7. Verify that the quota Used counter is correct by running the following command:

   $ oc describe quota gpu-quota -n nvidia

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   Example output

   Name:                    gpu-quota
   Namespace:               nvidia
   Resource                 Used  Hard
   --------                 ----  ----
   requests.nvidia.com/gpu  1     1

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8. Using the following command, attempt to create a second GPU pod in the nvidia namespace. This is technically available on the node because it has 2 GPUs:

   $ oc create -f gpu-pod.yaml

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   Example output

   Error from server (Forbidden): error when creating "gpu-pod.yaml": pods "gpu-pod-f7z2w" is forbidden: exceeded quota: gpu-quota, requested: requests.nvidia.com/gpu=1, used: requests.nvidia.com/gpu=1, limited: requests.nvidia.com/gpu=1

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   You recieve this Forbidden error message because you have a quota of 1 GPU and the pod tried to allocate a second GPU, which exceeds the allowed quota.