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Container Service for Kubernetes:CNFS overview

Last Updated:Jul 06, 2026

ACK introduces Container Network File System (CNFS) to improve NAS and OSS volume performance and QoS control, addressing imprecise quota control, accidental deletion recovery, missing capacity and performance metrics, encryption gaps, and small-file latency. This topic describes CNFS features, storage types, limits, usage notes, and billing.

Features

CNFS uses Kubernetes CRDs to manage Alibaba Cloud file storage instances, supporting create, delete, describe, mount, monitor, and scale operations.

Feature

CNFS version

Enable

Recycle bin

Enabled by default. Retains data for seven days.

Resource quotas

Storage resource quotas. Dynamically increase quota limits. See Use CNFS to auto-scale NAS volumes.

Enabled by default.

Volume monitoring

Monitors volume usage and I/O performance, includingpersistent volume claims (PVCs). See Overview of container storage monitoring.

Enabled after installing Managed Service for Prometheus.

Lifecycle management

Manages lifecycles of NAS file systems and OSS buckets.

Enabled by default.

Resource protection

Prevents accidental deletion of the entire file system.

Enabled by default.

Updates without service disruptions

Hot updates for volume drivers are supported.

Enabled by default.

End-to-end data acceleration

Mount volumes with Elastic File Client (EFC). See Mount NAS via EFC client with CNFS.

Disabled by default. Configure specific parameters to enable.

QoS

Configurable local cache size, cached metadata size, input/output operations per second (IOPS) limit, and throughput limit. See Enable the distributed caching feature of the CNFS client.

Default local cache: 128 MB. No default limit on cached metadata size, IOPS, or throughput.

Some advanced CNFS features, such as the recycle bin, resource quotas, and lifecycle management, can be configured only in the NAS console.

Storage types

NAS provides General-purpose NAS Capacity, General-purpose NAS Performance, and Extreme NAS file system types. See NAS types.

Limits

CNFS supports only ACK Pro clusters 1.20 or later.

Usage notes

Billing

References