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    File Storage NAS:What is NAS?

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    File Storage NAS:What is NAS?

    Last Updated:Jun 15, 2026

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

    Overview

    NAS uses POSIX-based APIs compatible with native operating systems. It provides shared access, data consistency, and mutual-exclusion locking. Multiple ECS instances can access the same file system simultaneously, and storage capacity scales automatically as files are added or removed. NAS serves as a shared data source for workloads and applications across multiple ECS instances or servers.

    NAS offers the following file system types: General-purpose Capacity NAS file systems, General-purpose Premium NAS file systems, General-purpose Performance NAS file systems, standard Extreme NAS file systems, and advanced Extreme NAS file systems. You can select one or more types based on your workloads to ensure high availability, security, and continuity. For more information, see Selection guide.

    • General-purpose NAS file systems: Store frequently accessed hot data. Classified into Capacity, Premium, and Performance tiers, General-purpose NAS file systems are suitable for enterprise Linux or Windows applications, web content management, database backup, log storage, and home directory services.

    • Extreme NAS file systems: A high-performance file sharing service built on the latest network architecture and all-flash storage. This fully managed service integrates with Alibaba Cloud compute services to deliver optimal performance. Extreme NAS file systems are suitable for latency-sensitive enterprise Linux applications, CI/CD development and test environments, high-performance web services, online education, online gaming, and databases.

    NAS supports various storage scenarios. For more information, see Scenarios.

    Benefits

    NAS provides cost-effectiveness, security, ease of use, high reliability, and high performance.

    • Cost-effectiveness

      • A single NAS file system can be mounted on multiple compute nodes simultaneously, eliminating the costs of large-scale copy and synchronization operations.

      • Performance scales linearly with storage capacity, removing the need for upfront investment in high-end storage devices.

      • Pay only for the storage you consume with no upfront provisioning, minimum consumption, or extra configuration cost. For more information, see Billing for General-purpose NAS.

      • Built-in high availability significantly reduces data security risks and maintenance costs.

    • Ease of use

      Create a file system in a few clicks — no deployment or O&M required.

    • Security

      NAS provides RAM-based access control, VPC-based access isolation, and encryption both in transit and at rest to prevent data theft and tampering.

    • High reliability

      NAS stores multiple data replicas across different devices in the same zone, delivering 99.999999999% (11 nines) data durability and 99.95% service availability.

    • High performance

      NAS distributed file systems scale performance linearly with capacity, outperforming traditional storage solutions.

    • Compatibility

      • Supports NFS and SMB protocols. Ensures data consistency and file locking based on POSIX APIs.

      • File modifications are visible in real time across all mount points.

    Features

    • Lifecycle management

      Lifecycle management reduces storage costs by automatically moving infrequently accessed files to cheaper storage classes. If files in a General-purpose NAS file system are accessed less than twice a month, enable lifecycle management to dump qualifying files to the Infrequent Access (IA) or Archive storage class at lower rates. For more information, see Configure lifecycle policies.

    • ACL

      • NAS SMB access control list (ACL): Manage user identities and access to SMB file systems through Active Directory (AD). Supports file system-level authentication based on Alibaba Cloud accounts and permission group-based whitelist access control with source IP addresses. For more information, see SMB ACL for File Storage NAS.

      • NAS NFS ACL: Grant fine-grained access permissions to specific users and groups beyond the standard owner, group, and other classes. Enable this feature in the NAS console. For more information, see NAS NFS ACL.

    • Quota management

      Create, modify, and delete directory quotas for NAS file systems. For more information, see Directory quotas.

    • Data encryption

      • Server-side encryption: NAS automatically encrypts stored data and decrypts it on access. For more information, see Server-side encryption.

      • Encryption in transit for NFS file systems: Uses TLS to protect data from theft or tampering during transmission between ECS instances and NAS. For more information, see Encryption in transit for NFS file systems.

      • Encryption in transit for SMB file systems: Uses Authenticated Encryption (AE) to protect data from theft or tampering during transmission between ECS instances and NAS. For more information, see Encryption in transit for SMB file systems.

    • Data backup

      Back up NAS file system data on a flexible schedule and restore files when data is lost or damaged. For more information, see General-purpose NAS backup.

    • Recycle bin

      Deleted files and directories are temporarily kept in the recycle bin along with their metadata (UID, GID, and ACL). You can restore accidentally deleted files from the recycle bin. For more information, see Recycle bin.

    Data erasure mechanisms

    Deleted data is completely erased from your NAS file system and cannot be accessed by other users. The following mechanisms ensure complete erasure:

    • Data in each NAS file system is fully isolated, managed, indexed, and verified through its own metadata. Cross-file-system reads are not allowed.

    • When a file is deleted, the metadata index is updated immediately so the corresponding physical space can no longer be indexed or read. When that physical space is reallocated, it is cleared before being added back to the index. First-time reads of the reallocated space return only zeros.

    • When a NAS file system is released, its metadata is destroyed immediately and the physical space is recycled. On reallocation, the space is cleared and overwritten by new data. All read requests return only zeros until new data is written.

    Usage notes

    To create, use, or release a NAS file system, use one of the following methods:

    • Use the NAS console

      NAS provides a web-based console. Log on to the NAS console to manage your NAS resources. For more information, see Get started with NAS.

    • Use the NAS API or NAS SDKs

      NAS provides RESTful API operations and SDKs for multiple programming languages. For more information, see Integration overview and NAS SDKs.

    NAS pricing

    For more information about the billing rules of File Storage NAS, see Billing for General-purpose NAS. For more information about the prices of NAS file systems, see File Storage NAS Pricing.

    Deactivate NAS

    • The NAS service cannot be deactivated. If you have activated NAS but you have not created a NAS file system, no fees are incurred.

    • If fees are incurred but you no longer want to use NAS, you can stop the billing of NAS. For more information, see How do I deactivate NAS or stop being charged for NAS? Note that the data of a deleted NAS file system cannot be restored.

    • To view the billing and usage details of NAS, go to the Expenses and Costs console. For more information, see Resource usage and bills.

    Related services

    After uploading data to NAS, you can use other Alibaba Cloud services to manage it.

    The following services are frequently used with NAS:

    • Elastic Compute Service: a cloud computing service that provides elastic and efficient computing capability. For more information, visit the product page of ECS.

    • Data Online Migration: You can use Data Online Migration to migrate data from Object Storage Service (OSS) to NAS. For more information, see Data Online Migration documentation.

    • Cloud Backup: You can use Cloud Backup to back up the files in a NAS file system on a regular basis and restore the files if data is lost or damaged. For more information, visit the product page of Cloud Backup.

    • Cloud Monitor: You can use CloudMonitor to view the performance metrics and storage usage metrics of NAS file systems. You can also configure alert rules for metrics. For more information, visit the product page of CloudMonitor.