AKS Learn feedback: Explain why to specify nobrl in mountOptions of statically provisioned PersistentVolume

[mloskot]

Type of issue

Missing information

Feedback

The PV example in the Statically provision a volume section displays the following mount options:

  mountOptions:
    - dir_mode=0777
    - file_mode=0777
    - uid=0
    - gid=0
    - mfsymlinks
    - cache=strict
    - nosharesock
    - nobrl

but there is no explanation on why the nobrl is needed or recomended?

The current official example in the azurefile-csi-driver repository does not present use of the nobrl option, see

• https://github.com/kubernetes-sigs/azurefile-csi-driver/blob/f0bf741efdd5b7941ee303cb5c7fc37eb940999f/deploy/example/pv-azurefile-csi.yaml#L15-L22

I also found this interesting blog by @chenghui-lee at https://lchenghui.com/nobrl-for-mount-cifs, screenshot with the fragment pasted below

Next, I found the nobrl documented in https://learn.microsoft.com/en-us/troubleshoot/azure/azure-kubernetes/storage/mountoptions-settings-azure-files#other-useful-settings which says:

It's necessary for certain applications that break with cifs-style mandatory byte range locks.

It would be useful if the current article on the statically provisioned PV-s expands on that, e.g. what types of applications are meant, is this locking effective on Windows containers too, etc.

Page URL

https://learn.microsoft.com/en-us/azure/aks/azure-csi-files-storage-provision#statically-provision-a-volume

Content source URL

https://github.com/MicrosoftDocs/azure-docs/blob/main/articles/aks/azure-csi-files-storage-provision.md

Author

@tamram

Document Id

b95ca0b2-e809-a149-dec7-a15ac2146ee1

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Document Details

⚠ Do not edit this section. It is required for learn.microsoft.com ➟ GitHub issue linking.

• ID: bdb3a253-ff94-1b97-62c9-e21153598452
• Version Independent ID: b95ca0b2-e809-a149-dec7-a15ac2146ee1
• Content: Create a persistent volume with Azure Files in Azure Kubernetes Service (AKS) - Azure Kubernetes Service
• Content Source: articles/aks/azure-csi-files-storage-provision.md
• Service: azure-kubernetes-service
• Sub-service: aks-storage
• GitHub Login: @tamram
• Microsoft Alias: tamram

[TPavanBalaji]

@mloskot
Thanks for your feedback! We will investigate and update as appropriate.