This topic describes Apsara File Storage NAS.
What is NAS?
NAS is a file storage service that Edge Node Service (ENS) provides for ENS instances. NAS is a distributed file system that provides the following benefits: shared access, scalability, high reliability, and high performance.
Overview
NAS provides shared access and ensures data consistency and exclusive locks. A NAS file system can be accessed by multiple ENS instances at the same time. The storage capacity of a NAS file system automatically increases or decreases when you add files to or remove files from the NAS file system. NAS provides a general-purpose data source for the workloads and applications that are generated on multiple instances or servers.
NAS provides two storage types: Capacity type and Extreme type. You can select an appropriate storage type based on your business requirements.
Capacity type
A Capacity NAS file system is used to store hot data that is frequently accessed. It is suitable for general-purpose file sharing services such as Linux- or Windows-based enterprise applications, web content management, database backup, and log storage.
Extreme type
An Extreme NAS file system is a high-performance shared file storage service based on all-flash storage. It is suitable for latency-sensitive enterprise applications, high-performance web services, gaming services, and databases.
Benefits
NAS provides the following benefits:
Ease of use: You can create a NAS file system with a few clicks without the need to deploy or maintain the NAS file system.
Shared access: A NAS file system can be mounted on multiple ENS instances and accessed by multiple ENS instances at the same time. This reduces copy and synchronization costs. After a file is modified, you can immediately view the modification result. This way, you can modify storage data in real time.
Pay-as-you-go: You are charged for a NAS file system based on the storage space that you use. You do not need to specify storage space in advance, and no minimum fees are charged.
High security: NAS implements network access isolation based on Virtual Private Cloud (VPC) to ensure data access security and prevent data theft or tampering.
High reliability: NAS uses a triplicate mechanism. Three replicas of each data record are stored on different devices. This ensures at least 99.9999% data reliability.
Billing
NAS uses the pay-as-you-go billing method. The usage of all resources is calculated on an hourly basis. Bills are settled based on the actual resource usage. Fees are deducted after resources are used.
Fees are calculated based on the following formula: Fee = Resource usage × Unit price of the resource per hour
Item | Description |
Billing rules | You are charged based on the resource usage. Bills are generated and fees are deducted from the balance of your Alibaba Cloud account after a billing cycle ends. |
Billing cycle | Fees are calculated on an hourly basis and deducted in real time. In most cases, bills are generated after a billing cycle ends. The specific time when bills are generated is determined by the system. |
Billable items and pricing |
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Limits
You can use an Alibaba Cloud account to create up to two NAS file systems for each edge node.
You can add only one mount target for each NAS file system.
You can mount a NAS file system only on a compute node that resides in the same VPC as the mount target of the NAS file system.
Only Network File System (NFS) V3 and NFS V4.0 are supported.