NAS volume overview - Container Service for Kubernetes - Alibaba Cloud Documentation Center

You can use Apsara File Storage NAS (NAS) volumes in ACK Serverless clusters. This topic describes the features, types, use scenarios, limits, and billing rules of NAS volumes.

Description

Apsara File Storage NAS is a cloud service that provides a file storage solution for compute nodes. The compute nodes include Elastic Compute Service (ECS) instances, Elastic High-Performance Computing (E-HPC) instances, and Container Service for Kubernetes (ACK) clusters. NAS is a distributed file storage solution that provides shared access, scalability, high reliability, and high performance.

NAS uses Portable Operating System Interface of UNIX (POSIX)-based APIs and is compatible with native operating systems. NAS provides shared access, ensures data consistency, and implements mutual exclusion by using locks. NAS provides scalable file systems and allows simultaneous access to a NAS file system from multiple ECS instances. The storage capacity of a NAS file system automatically scales in or out when you add or remove files. NAS provides shared data sources for workloads and applications that run on multiple ECS instances or servers.

Storage types

NAS provides the following file system types: General-purpose NAS Capacity, General-purpose NAS Performance, and Extreme NAS. For more information, see NAS types.

Use scenarios

NAS provides shared storage. You can mount NAS file systems as statically provisioned volumes to meet the requirements of diverse scenarios.
In ACK Serverless clusters, you can mount only statically provisioned NAS volumes. Dynamically provisioned NAS volumes are not supported. For more information about how to mount statically provisioned NAS volumes, see Mount a statically provisioned NAS volume.

Usage notes

NAS is a shared storage service. A persistent volume claim (PVC) that is used to mount a NAS file system can be used by multiple pods.
Do not delete the mount target before you unmount the NAS file system. Otherwise, an operating system hang issue may occur.
After a mount target is created, wait until its status changes to Available and then use the volume.
We recommend that you use the NFSv3 file sharing protocol.
General-purpose and Extreme NAS file systems have different limits on mounting scenarios, the number of file systems, and file sharing protocols. For more information, see Limits.
After you delete a persistent volume (PV) of the subpath type in an ACK Serverless cluster, the subdirectory is not deleted. This means that even if the reclaimPolicy of a PV is set to Delete and the PV is deleted, the corresponding directory in the NAS file system is not deleted. You need to manually mount the subdirectory and delete it.

Billing

For more information about the billing of NAS, see NAS billing overview.