Container Service for Kubernetes (ACK) Edge clusters reuse the Container Storage Interface (CSI) plug-ins (csi-plugin and csi-provisioner) from ACK clusters. This ensures that their behavior on Elastic Compute Service (ECS) instances is identical to their behavior in ACK clusters. For more information, see Storage. This topic describes the usage and limits of the CSI plug-ins for different node types and connection types.
Limits
CSI plug-in limits
When you use the storage CSI plug-ins, note the limits of the plug-ins and the supported Alibaba Cloud storage products. For more information, see Limits of storage CSI plug-ins.
Determine the storage volume capabilities that the CSI plug-ins support based on your node type and connection type.
Cluster version limits
To use CSI plug-ins, ensure that your ACK Edge cluster is version 1.14 or later and the kubelet parameter
--enable-controller-attach-detachis set totrue.To use ECS disks, ensure that your ACK Edge cluster is version 1.24 or later.
To use ENS disks, ensure that your ACK Edge cluster is version 1.20 or later.
Overview of container storage capabilities
The Container Storage Interface (CSI) plug-in is the implementation solution recommended by the Kubernetes community. The container storage feature of ACK Edge clusters is also based on CSI plug-ins. The plug-ins are fully compatible with native Kubernetes volume types, such as EmptyDir, HostPath, Secret, and ConfigMap.
When an ENS node uses Alibaba Cloud NAS and CPFS (note: not the NAS from ENS), you must connect the node to the cluster's VPC through an Express Connect circuit. You can submit a ticket for assistance.
If you use Logical Volume Manager (LVM) for local storage, ensure that cloud nodes can access the storage nodes on TCP port 1736. For more information, see Use LVM for local storage.
Introduction to CSI components
The CSI components for an ACK Edge cluster include csi-plugin, csi-provisioner, csi-ens-plugin, and csi-ens-provisioner. You must install them manually. For more information, see Manage components.
To use ENS disks, install the csi-ens-plugin and csi-ens-provisioner components. For other volumes, install the csi-plugin and csi-provisioner components.
The following table lists the supported volumes and corresponding user guides based on the node type and connection type.
Node type | Storage service | Statically provisioned volume | Dynamically provisioned volume | Action Links |
ECS | Alibaba Cloud disk | Supported | Supported | |
Alibaba Cloud NAS | Supported | Supported | ||
Alibaba Cloud CPFS | Supported | Supported | ||
Alibaba Cloud OSS | Supported | Supported | ||
Local storage | Supported | Supported | ||
ENS | ENS disk | Supported | Supported | |
Alibaba Cloud NAS (connected over an Express Connect circuit) | Supported | Supported | ||
Alibaba Cloud CPFS (connected over an Express Connect circuit) | Supported | Supported | ||
Alibaba Cloud OSS | Supported | Not supported | ||
Local storage | Supported | Supported | ||
Express Connect Edge nodes connected over an Express Connect circuit | Alibaba Cloud NAS | Supported | Supported | |
Alibaba Cloud CPFS | Supported | Supported | ||
Alibaba Cloud OSS | Supported | Not supported | ||
Local storage | Supported | Supported | ||
Access from the Internet Edge nodes connected over the internet | Alibaba Cloud OSS | Supported | Not supported |
Upgrade CSI-related components
You can view the versions of CSI-related components and upgrade the components in the console.
Log on to the ACK console. In the left navigation pane, click Clusters.
On the Clusters page, find the one you want to manage and click its name. In the left navigation pane, click Add-ons.
Click the Storage tab. In the sections for the csi-ens-plugin, csi-ens-provisioner, csi-plugin, and csi-provisioner components, check the current versions and upgrade the components if needed.