Local storage volumes do not provide high availability and are applicable only to scenarios where temporary storage is required or where applications can provide high availability. You can use the Container Storage Interface (CSI) component to mount local storage volumes to Container Service for Kubernetes (ACK) clusters. This topic describes the types of local storage volumes supported by ACK and the use scenarios of the volume types.
Use scenarios
The storage media of local storage volumes can be local disks and cloud disks provided by Alibaba Cloud and memory, which provides temporary local storage.
Local storage is suited for scenarios that require high storage I/O performance, mass storage, and high cost-efficiency. Local storage volumes do not provide high availability and are applicable only to scenarios where temporary storage is required or where applications can provide high availability.
The following table describes different types of local storage volumes.
Type | Description |
This type of volume is provided by Kubernetes. You can use a hostPath volume to automatically create a directory if no directory exists in the mount path. Pods that are mounted with hostPath volumes can be migrated among nodes. You can use a hostPath volume to mount a file or directory from the file system of the host node to a pod. | |
This type of volume is provided by Kubernetes. Pods that are mounted with local volumes cannot be migrated. If you want to migrate a pod mounted with a local volume to another node, you must add specific labels to the node. You can use a local volume to mount a local storage device to a pod, such as a disk, partition, or directory. | |
After you use volume groups (VGs) to virtualize disks, you can use Logical Volume Manager (LVM) to divide the VGs into LVs and mount the LVs to upper-layer applications. LVs cannot be migrated across nodes. Therefore, LVs are not suitable for high availability scenarios. | |
You can use the project quota feature of file systems on local disks, such as the Ext4 file system. The project quota feature allows you to control the disk quota at the directory level. You can also use the CSI plug-in to manage the lifecycle of QuotaPath volumes, such as division, quota limit, and mounting of QuotaPath volumes. | |
Memory volumes virtualize memory resources as a tmpfs (RAM-backed filesystem). You can mount a memory volume to provide fast local storage. |
Storage specifications
Alibaba Cloud provides the following types of local disks: non-volatile memory express (NVMe) SSD and SATA HDD. For more information, see Local disks.
Billing
Fees for local disks are included in the fees for the instances to which the disks are attached. For more information, see Subscription and Pay-as-you-go.