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Apsara File Storage NAS:NAS volume overview

Last Updated:Jul 28, 2023

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

Features

NAS is a cloud service that provides a file storage solution for compute nodes, such as Elastic Compute Service (ECS) instances, nodes in Elastic High-Performance Computing (E-HPC) clusters, and nodes in 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 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.

NAS file system 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

The following table describes the operations that you can perform on a NAS volume to meet your business requirements.

Business requirement

References

Use CNFS to manage NAS file systems (recommended)

You can use Container Network File System (CNFS) to manage the lifecycles of Apsara File Storage NAS (NAS) file systems. This ensures data security, enables data sharing, and accelerates access to NAS file systems. CNFS provides distributed caching services that support multiple parallel connections, allow you to read and write data cache at the client side, and support the Lease mechanism. These features can accelerate read and write operations for NAS file systems. This way, NAS file systems can provide a user experience similar to local file systems. For more information, see the following topics:

Use CNFS to persist application data (recommended)

For more information, see the following topics:

Use CNFS to automatically expand NAS volumes

You can configure expansion policies to automatically expand NAS volumes when the capacity usage exceeds a threshold. For more information, see Use CNFS to automatically expand NAS volumes.

Accelerate data access in parallel computing scenarios

You can create distributed cache pools based on the memory of compute nodes. The cache pools can automatically scale in or out based on the computing demand to accelerate access to hot data in NAS volumes. We recommend that you use CNFS to accelerate data access in AI training and genomics computing scenarios. For more information, see Enable the distributed caching feature of the CNFS client.

Persist application data without using CNFS

For more information, see the following topics:

Set quotas for NAS volumes without using CNFS

You can set quotas on the directories of NAS volumes to manage the storage space of NAS volumes. For more information, see Expand a NAS volume.

Note

If your NAS file system is managed by using CNFS, no additional configuration is required.

Limits

  • NAS is a shared storage service. A 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, the operating system hang may occur.

  • After a mount target is created, wait until the state of the mount target changes to Available.

  • We recommend that you use NFSv3.

  • Before you use NAS volumes, we recommend that you upgrade the CSI plug-in to the latest version.

  • 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.

Billing

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