Merge pull request #283 from songjiaxun/limitation_page

doc: add separate limitation page

Author: k8s-ci-robot

README.md

@@ -44,9 +44,7 @@ Please refer to [install Azure Blob Storage CSI driver](https://github.com/kuber
  - [CSI driver troubleshooting guide](./docs/csi-debug.md)
 
  ### Limitations
- - Although Blob CSI Driver allows ReadWriteMany access mode to be used, its functionality is limited by the underlying volume-mounting technology. If azure-storage-fuse is being used to mount a Blob storage container, multiple nodes are allowed to mount the same container, but for just read-only scenarios. It means, you can still use ReadWriteMany mode to claim a volume, but you should carefully avoid writing to one single file from multiple nodes as there will be data corruption. NFSv3, in the contrast, fully supports ReadWriteMany access mode.
- - The azure-storage-fuse method only supports Linux agent nodes.
- - For the Kubernetes clusters that are running on Azure Stack Hub environments, only Standard Locally-redundant storage (Standard_LRS) Storage Account is supported. You will not be blocked if you claim a volume with other types of Storage Account but under the hood, the account type will be converted to Standard_LRS.
+Please refer to [Azure Blob Storage CSI Driver Limitations](./docs/limitations.md)
 
 ## Kubernetes Development
 Please refer to [development guide](./docs/csi-dev.md)

docs/limitations.md

@@ -0,0 +1,6 @@
+# Azure Blob Storage CSI Driver Limitations
+ - Although Blob CSI Driver allows ReadWriteMany access mode to be used, its functionality is limited by the underlying volume-mounting technology. If azure-storage-fuse is being used to mount a Blob storage container, multiple nodes are allowed to mount the same container, but for just read-only scenarios. It means, you can still use ReadWriteMany mode to claim a volume, but you should carefully avoid writing to one single file from multiple nodes as there will be data corruption. NFSv3, in the contrast, fully supports ReadWriteMany access mode.
+ - The azure-storage-fuse method only supports Linux agent nodes.
+ - For the Kubernetes clusters that are running on Azure Stack Hub environments, only Standard Locally-redundant storage (Standard_LRS) Storage Account is supported. You will not be blocked if you claim a volume with other types of Storage Account, however, under the hood the account type will be converted to Standard_LRS.
+ - The memory consumption of azure-storage-fuse (blobfuse) may be high when large files are being processed. Thus, by default the Blob CSI Driver container has a memory restriction of 2100Mi. This known issue is described in [this ticket](https://github.com/Azure/azure-storage-fuse/issues/454).
+ - Restart csi-blobfuse-node daemonset would make current blobfuse mount unavailable. This issue is tracked by [this ticket](https://github.com/kubernetes-sigs/blob-csi-driver/issues/115).