# storage-driver (System Resource Add-on, Mandatory)

#### Introduction

storage-driver functions as a standard Kubernetes FlexVolume plug-in to allow containers to use IaaS storage resources. By installing and upgrading storage-driver, you can quickly install and update cloud storage capabilities.

storage-driver is a system resource add-on. It is installed by default when a cluster of Kubernetes v1.13 or earlier is created.

#### Notes and Constraints

- For clusters created in CCE, Kubernetes v1.15.11 is a transitional version in which the FlexVolume plug-in (storage-driver) is compatible with the CSI plug-in (everest). Clusters of v1.17 and later versions do not support FlexVolume any more. You need to use the everest add-on. For details about CSI and FlexVolume, see Differences Between CSI and FlexVolume Plug-ins.
- The FlexVolume plug-in will be maintained by Kubernetes developers, but new functionality will only be added to CSI. You are advised not to create storage that connects to the FlexVolume plug-in (storage-driver) in CCE any more. Otherwise, the storage resources may not function normally.
- This add-on can be installed only in clusters of v1.13 or earlier. By default, the everest add-on is installed when clusters of v1.15 or later are created.

  In a cluster of v1.13 or earlier, when an upgrade or bug fix is available for storage functionalities, you only need to install or upgrade the storage-driver add-on. Upgrading the cluster or creating a cluster is not required.

#### Installing the Add-on

This add-on has been installed by default. If it is uninstalled due to some reasons, you can reinstall it by performing the following steps:

If storage-driver is not installed in a cluster, perform the following steps to install it:

1. Log in to the CCE console. In the navigation pane, choose Add-ons. On the Add-on Marketplace tab page, click Install Add-on under storage-driver.
2. On the Install Add-on page, select the cluster and the add-on version, and click Next: Configuration.
3. Click Install to install the add-on. Note that the storage-driver has no configurable parameters and can be directly installed.

   After the add-on is installed, click Go Back to Previous Page. On the Add-on Instance tab page, select the corresponding cluster to view the running instance. This indicates that the add-on has been installed on each node in the cluster.

#### Upgrading the Add-on

1. Log in to the CCE console. In the navigation pane, choose Add-ons. On the Add-on Instance tab page, select the target cluster and click Upgrade under storage-driver.

   - If the Upgrade button is unavailable, the current add-on is already up-to-date and no upgrade is required.
   - When the upgrade is complete, the original storage-driver version on cluster nodes will be replaced by the latest version.
2. On the Basic Information page, select the add-on version and click Next.
3. Click Upgrade to upgrade the storage-driver add-on. Note that the storage-driver has no configurable parameters and can be directly upgraded.

#### Uninstalling the Add-on

1. Log in to the CCE console. In the navigation pane, choose Add-ons. On the Add-on Instance tab page, select the target cluster and click Uninstall under storage-driver.
2. In the dialog box displayed, click Yes to uninstall the add-on.

Parent topic: Add-ons