The Container Storage Interface (CSI) plug-in of Container Service for Kubernetes (ACK) clusters is reused in the CSI plug-in of ACK Edge clusters, such as in csi-plugin and csi-provisioner. You can use the CSI plug-in on Elastic Compute Service (ECS) instances in the same way as you use the CSI plug-in in ACK clusters. For more information, see CSI overview. This topic describes differences in the usage and limits of the CSI plug-in with ACK clusters under different types and access modes of the node.
Limits
CSI plug-in limits
When you use the CSI plug-in in ACK clusters, take note of the limits on the CSI plug-in and Alibaba Cloud storage services. For more information, see Limits.
Determine the storage volume capabilities supported by the CSI plug-in based on the type and access mode of your node.
Cluster version limits
To use the CSI plug-in, make sure that the version of the ACK Edge cluster is 1.14 or later. Besides, the kubelet parameter
--enable-controller-attach-detachmust be set totrue.To use ECS disks, make sure that the version of the ACK Edge cluster is 1.24 or later.
To use Edge Node Service (ENS) disks, make sure that the version of the ACK Edge cluster is later than 1.20.
Overview of container storage
The container storage capability of ACK Edge clusters is developed based on the CSI plug-in, which is the plug-in solution recommended by the Kubernetes community. CSI enables compatibility with native Kubernetes storage services, such as emptyDir, HostPath, Secret, and ConfigMap. The following figure describes details of the volumes supported by the CSI plug-in based on the type and access mode of the node.
If your ENS node uses Apsara File Storage (NAS) file systems and Cloud Parallel File Storage (CPFS) file systems (note: not the NAS file system in ENS instances), you need to connect it to the virtual private cloud (VPC) where the cluster is deployed using an Express Connect circuit. You can submit a ticket for consultation.
If you use the Logical Volume Manager (LVM) to manage local storage, ensure that the TCP 1736 port of the node where the storage is deployed can be accessed from the cloud node. For more information, see Use LVM to manage local storage.
Introduction to CSI plug-in
The CSI plug-in of the ACK Edge cluster consists of csi-plugin, csi-provisioner, csi-ens-plugin, and csi-ens-provisioner. By default, these plug-ins are not installed and you must install them manually. For more information, see Manage components.
You must install the csi-ens-plugin and csi-ens-provisioner plug-ins to use ENS disks. For other volumes, you must install the csi-plugin and csi-provisioner plug-ins.
The following table describes details of the volumes supported by the CSI plug-in based on the type and access mode of the node.
Node type | Storage service | Statically provisioned volume | Dynamically provisioned volume | Reference |
ECS | Alibaba Cloud disk | Supported | Supported | |
NAS | Supported | Supported | ||
OSS | Supported | Not supported | ||
Local storage | Supported | Supported | ||
ENS | NAS (connected over Express Connect) | Supported | Supported | |
OSS | Supported | Not supported | ||
Local storage | Supported | Supported | ||
Edge nodes connected over Express Connect | NAS | Supported | Supported | |
OSS | Supported | Not supported | ||
Local storage | Supported | Supported | ||
Edge nodes connected over the Internet | OSS | Supported | Not supported | |
Local storage | Supported | Supported |
Upgrade CSI-related plug-ins
You can check and upgrade CSI-related plug-ins in the console.
Log on to the ACK console. In the left-side navigation pane, click Clusters.
On the Clusters page, find the cluster that you want to manage and click its name. In the left-side navigation pane, choose .
Click the Storage tab, and in the csi-ens-plugin, csi-ens-provisioner, csi-plugin, and csi-provisioner component areas, check the current versions of the plug-ins to determine whether an upgrade is required.