All Products
Search
Document Center

File Storage NAS:Billing of General-purpose NAS file systems

Last Updated:Feb 11, 2025

This topic describes the pricing, billable items, billing methods, and billing examples of General-purpose NAS file systems (Capacity, Performance, and Premium).

Pricing of General-purpose NAS file systems

For more information about the pricing of each billable item, see File Storage NAS Pricing.

Storage usage fees are calculated in USD per GiB-month. When you use the pay-as-you-go billing method, fees are calculated based on the following formula: Fees = Storage usage × Unit price per hour. Therefore, when you calculate storage usage fees, you must convert GiB-month to GiB-hour by using the following formula: Unit price in GiB-hour = Unit price in USD per GiB-month/30/24.

For example, the unit price of a Capacity NAS file system is USD 0.06 per GiB-month. The unit price settled on an hourly basis is approximately USD 0.000083333 per GiB-hour (0.06/30/24).

Billable items of General-purpose NAS file systems

Basic fee

Billable item

Code

Description

Storage Usage of General-purpose NAS File System (Capacity/Performance)1

VolumeSize

You are charged for the storage usage of a General-purpose NAS file system based on the storage class (Capacity, Premium, or Performance), maximum storage usage per hour, and storage duration.

For more information about how to view the storage usage of a file system, see View the details of a file system or Resource usage and bills.

Fees of value-added features

Fees are incurred if you enable and use the lifecycle management (IA and Archive storage) and recycle bin features for a General-purpose NAS file system.

Feature

Billable item

Code

Description

Infrequent Access (IA) storage class

Storage Usage of IA Storage Class1

VolumeIASize

You are charged based on the maximum storage usage of the IA storage class per hour.

Read Traffic of IA Data2

InfrequentReadQuantity

Traffic fees are incurred when the data in the IA storage class is accessed. Fees are calculated based on the total amount of read and write traffic per hour.

The amount of read and write traffic is reset to 0 each time an hourly bill is generated. The amount of read and write traffic starts from 0 again for the next hour.

Write Traffic of IA Data2

InfrequentWriteQuantity

Archive storage class

Storage Usage of Archive Storage Class1

VolumeArchiveSize

You are charged based on the maximum storage usage of the Archive storage class per hour.

Storage Usage of Archive Data Retained for Less Than 60 Days

ArchivePenaltyQuantity

If a file in the Archive storage class is deleted or reduced in size but the file is stored for less than 60 days (1,440 hours), you are charged for the remaining storage duration (1,440 - Actual storage duration) based on the original file size.

Note

The minimum storage duration starts from the time when a file is accessed, which is indicated by the atime parameter.

Read Traffic of Archive Data2

ArchiveReadQuantity

Traffic fees are incurred when the data in the Archive storage class is accessed. Fees are calculated based on the total amount of read and write traffic per hour.

The amount of read and write traffic is reset to 0 each time an hourly bill is generated. The amount of read and write traffic starts from 0 again for the next hour.

Write Traffic of Archive Data2

ArchiveWriteQuantity

Recycle bin

After you enable the recycle bin feature, you are charged for the storage usage of the temporary files in the recycle bin based on the pricing of the original storage class during the retention period.

Examples:

  • For example, if you delete a file from a Capacity NAS file system, you are charged for the file based on the unit price of storage space in Capacity NAS file systems.

  • If you delete a file from the IA or Archive storage class, you are charged for the file based on the unit price of storage space in the IA or Archive storage class.

If you enable the recycle bin or lifecycle management feature for a file system, the billed storage usage is larger than the actual storage usage. For more information about the billed storage usage of each storage class, see View the details of a file system or Query the usage details of file systems.

  • Note 1: Storage usage

    • The storage usage of a NAS file system indicates the total size of all files in the file system. The size of directories is not included. The basic storage unit is 4 KiB. If the size of a file is less than 4 KiB, the billed storage usage of the file is rounded up to 4 KiB. If the size of a file is larger than 4 KiB, the billed storage usage is rounded up to the nearest multiple of 4 KiB. For example, if the size of a file is 2 KiB, the storage usage is counted as 4 KiB. If the size of a file is 6 KiB, the storage usage is counted as 8 KiB.

    • File holes occupy storage space in File Storage NAS. You are charged for the file holes in your NAS file systems. A file hole consists of zeros that are not written to a file. You can create a file hole by running the truncate, lseek, or fallocate command.

    • By default, the data of General-purpose NAS file systems is stored in the Standard storage class. To ensure the performance of a file system, infrequently accessed files are dumped only in batches. Dumped files no longer occupy the storage space of the original storage class. For more information, see Storage classes of General-purpose NAS file systems. When the files are being dumped, each file has a replica in the storage space of the original storage class and the new storage class. This temporarily increases storage usage and generates additional fees. After the files are dumped, the file replicas in the original storage class are deleted and no longer generate additional fees.

  • Note 2: Read and write traffic

    • If the data in a file system meets the rule specified in the lifecycle policy, the data is automatically dumped to the IA or Archive storage class. No write traffic fees are generated for the data transfer.

    • If you access files in the IA or Archive storage class, you are charged for the actual read and write traffic that is generated. If you read only a part of a file, you are charged for the read traffic that is generated.

    • When you read data from or write data to the IA or Archive storage class, you are charged for the read and write traffic regardless of the network environment.

    • If you run a data retrieval task, you are charged for read traffic based on the size of the retrieved files.

    • If you back up files from the IA or Archive storage class, you are charged for read traffic based on the size of the files.

    • If you use security services such as the anti-ransomware service of Security Center to scan files in the IA or Archive storage class, you are charged for the actual read and write traffic that is generated.

    • You are not charged for managing metadata in the IA or Archive storage class. For example, you are not charged for running the ls command to show the metadata of specified files.

Billing methods

The default billing method of General-purpose NAS file systems is pay-as-you-go. After you create a General-purpose NAS file system, you can purchase resource plans and storage capacity units (SCUs) to offset storage usage fees.

Select billing methods

Before you use a file system, we recommend that you select appropriate billing methods to reduce storage costs. The following table describes the characteristics and scenarios of different billing methods.

Billing method

Description

Characteristics

Use scenario

Pay-as-you-go

By default, you are charged for all billable items based on the pay-as-you-go billing method. You are charged for the actual usage of each billable item. Pay-as-you-go allows you to use resources first and pay for them afterwards.

The storage usage fluctuates and is difficult to predict.

  • Business with fluctuating resource usage

  • Business that requires temporary use of resources

Resource plans

A resource plan is a favorable billing method that can be used to offset fees for various billable items. When bills are being settled, resource plans have higher priority than the pay-as-you-go billing method. Before you can use resource plans to offset fees, you must purchase resource plans.

The storage usage of each file system is relatively stable and predictable.

For stable storage usage, you can purchase resource plans to reduce storage costs.

Important

Resource plans offset fees based on specific offset factors, depending on the file system type and storage class. For more information, see Resource plans.

Storage plans (no longer available for purchase)

A storage plan is a billing method that can be used to offset fees for specific billable items. Before you can use storage plans to offset fees, you must purchase storage plans.

You can use a storage plan to offset only the storage usage fees of a NAS file system to which the storage plan is attached. Only the fees for the Standard storage class and the IA storage class can be offset.

We recommend that you do not use storage plans because storage plans are no longer available for purchase.

SCUs

An SCU is a billing method that can be used to offset fees for specific billable items. Before you can use SCUs to offset fees, you must purchase SCUs.

SCUs can be used to offset the storage usage fees of Capacity NAS file systems, Performance NAS file systems, and other Alibaba Cloud storage services.

You use services such as Object Storage Service (OSS), snapshot service, and Cloud Backup in addition to File Storage NAS.

Billing methods supported by each billable item

The following table describes the billing methods supported by each billable item of General-purpose NAS file systems.

Note

If you have resource plans, SCUs, and storage plans within your Alibaba Cloud account, storage usage fees are offset based on the following order: storage plans, resource plans, and SCUs. Then, you are charged based on the pay-as-you-go billing method. The following figure shows the offset order.抵扣顺序

Billable item

Pay-as-you-go

Resource plans

Storage plans (no longer available for purchase)

SCUs

Storage Usage of General-purpose NAS File System (Capacity/Performance)

Supported

Supported

Only the storage usage fees of Capacity NAS file systems and Performance NAS file systems can be offset. The storage usage fees of Premium NAS file systems cannot be offset.

Storage Usage of IA Storage Class

Supported

Supported

Supported

Not supported

Read Traffic of IA Data

Supported

Not supported

Not supported

Not supported

Write Traffic of IA Data

Supported

Not supported

Not supported

Not supported

Storage Usage of Archive Storage Class

Supported

Supported

Not supported

Not supported

Storage Usage of Archive Data Retained for Less Than 60 Days

Supported

Not supported

Not supported

Not supported

Read Traffic of Archive Data

Supported

Not supported

Not supported

Not supported

Write Traffic of Archive Data

Supported

Not supported

Not supported

Not supported

Example of cost optimization

By default, the data of General-purpose NAS file systems is stored in the Standard storage class. When you use General-purpose NAS file systems, you can select appropriate storage classes based on the changes of business data, and effectively reduce storage costs by combining the subscription and pay-as-you-go billing methods.

For example, you have 20 GiB of hot data, 60 GiB of IA data, and 20 GiB of cold data that needs to be stored for a long time. You create a General-purpose NAS file system in the China (Hangzhou) region. The following tables demonstrate the monthly costs for different storage classes.

Note

The unit prices listed in the following tables are for reference only. To view the actual prices, visit the File Storage NAS Pricing page.

All data stored in the Standard storage class

File system

Data volume

Unit price

Storage fee

Capacity NAS file system

100 GiB

USD 0.06 per GiB-month

USD 6

Premium NAS file system

USD 0.13 per GiB-month

USD 13

Performance NAS file system

USD 0.3 per GiB-month

USD 30

Assume that 20 GiB of hot data is stored in the Standard storage class, 60 GiB of IA data is dumped to the IA storage class, and 20 GiB of cold data that needs to be stored for a long time is dumped to the Archive storage class.

The following table describes the fees that you need to pay after you convert the storage class and use resource plans.

File system

Converted base capacity3

Fee of General-purpose NAS resource plan

Capacity NAS file system

Converted base capacity = 20 GiB × 1 + 60 GiB × 0.37 + 20 GiB × 0.17 = 48.6 GiB

If you purchase a 100 GiB resource plan, the fee is USD 4.57.

Premium NAS file system

Converted base capacity = 20 GiB × 2.45 + 60 GiB × 0.37 + 20 GiB × 0.17 = 74.6 GiB

If you purchase a 100 GiB resource plan, the fee is USD 4.57.

Performance NAS file system

Converted base capacity = 20 GiB × 5.47 + 60 GiB × 0.37 + 20 GiB × 0.17 = 135 GiB

If you purchase a 200 GiB resource plan, the fee is USD 9.14.

Note 3: Converted base capacity

When you use NAS resource plans to offset storage usage fees, the offset factor varies depending on the file system type, the storage class, and the region of the file system. When you purchase resource plans, you need to convert prices according to the preceding information. For more information, see Offset factors.

As shown in the preceding tables:

  • If data is stored in a Capacity NAS file system, you can save 23.83% of the storage cost by converting the storage class and using resource plans, compared with storing all data in the Standard storage class.

  • If data is stored in a Premium NAS file system, you can save 64.85% of the storage cost by converting the storage class and using resource plans, compared with storing all data in the Standard storage class.

  • If data is stored in a Performance NAS file system, you can save 69.53% of the storage cost by converting the storage class and using resource plans, compared with storing all data in the Standard storage class.

Billing examples

The following examples show how you are charged for NAS in common scenarios.

Note

The unit prices listed in the following tables are for reference only. To view the actual prices, visit the File Storage NAS Pricing page.

Example 1: Share data for web services

On November 1, 2024, Mr. Wang deployed a shared-storage web service in a Capacity NAS file system in the China (Hangzhou) region. The service is expected to use 500 GiB of storage capacity per hour. In this case, the total fee of the month is USD 30, as shown in the following table.

Operation

Billable item

Code

Unit price

Billable amount

Fee

Store 500 GiB of data

Storage Usage of General-purpose NAS File System (Capacity/Performance)

VolumeSize

USD 0.06 per GiB-month

500 GiB per month

USD 30

Example 2: Access IA data

Mr. Zhang created a Performance NAS file system in the China (Hangzhou) region. The storage usage of the file system is 100 GiB per hour in November 2024. 10 GiB of data is stored in the Standard storage class, and 90 GiB of data is stored in the IA storage class. The read traffic of the IA storage class is 1 GiB and the write traffic of the IA storage class is 2 GiB within the month. In this case, the total fee of the month is USD 5.11767, as shown in the following table.

Operation

Billable item

Code

Unit price

Billable amount

Fee

Store 10 GiB of data in the Standard storage class

Storage Usage of General-purpose NAS File System (Capacity/Performance)

VolumeSize

USD 0.3 per GiB-month

10 GiB per month

USD 3

Store 90 GiB of data in the IA storage class

Storage Usage of IA Storage Class

VolumeIASize

USD 0.02322 per GiB-month

90 GiB per month

USD 2.0898

Read 1 GiB of data from the IA storage class

Read Traffic of IA Data

InfrequentReadQuantity

USD 0.00929 per GiB-month

1 GiB per month

USD 0.00929

Write 2 GiB of data to the IA storage class

Write Traffic of IA Data

InfrequentWriteQuantity

2 GiB per month

USD 0.01858

Example 3: Implement cross-region disaster recovery based on NAS file systems

On November 1, 2024, Mr. Zhang stored 150 GiB of files in a Performance NAS file system (File System A) in the China (Beijing) region. To further improve the security and reliability of data and prevent data loss or access interruptions caused by failures in a single region, Mr. Zhang created a cross-region backup policy for the file system to back up data on a regular basis. If exceptions such as natural disasters and power failures occur in a region, Mr. Zhang can still use the data in the backup vault to recreate a file system (File System B), thus ensuring business continuity. In this case, the total fee of the month is USD 59.5418, as shown in the following table.

Operation

Billable item

Code

Unit price

Billable amount

Fee

Store 150 GiB of data

Storage Usage of General-purpose NAS File System (Capacity/Performance)

VolumeSize

USD 0.3 per GiB-month

150 GiB

USD 45 (included in your NAS bills)

Back up files by using a cross-region backup policy created in Cloud Backup

Storage Space

Storage

USD 0.03187 per GiB-month

140 GiB3

USD 4.4618 (included in your Cloud Backup bills)

Cross-region replication traffic

Traffic

USD 0.072 per GiB

140 GiB

USD 10.08 (included in your Cloud Backup bills)

3 When you back up data, Cloud Backup deduplicates and compresses the data. Therefore, the amount billed in this scenario is the amount of deduplicated and compressed data.

Example 4: Automatically dump and clean up NAS data

On November 1, 2024, Mr. Zhang created a Capacity NAS file system in the China (Beijing) region. The storage usage of the file system is 1,000 GiB per hour. All files are stored in the /mnt directory. To cope with changes in access requirements at different phases, Mr. Zhang configured the following lifecycle rules:

  1. Phase 1: Data needs to be frequently accessed in this phase. All files in the /mnt directory are stored in the Standard storage class. This phase lasts 14 days.

  2. Phase 2: Data is accessed less than once within 14 days. All files in the /mnt directory are dumped to the IA storage class. This phase lasts 16 days.

  3. Phase 3: Data is accessed less than once within 30 days. All files in the /mnt directory are dumped to the Archive storage class. This phase lasts 5 days.

  4. Phase 4: Data no longer needs to be retained. Delete all files in the /mnt directory after data is stored in the Archive storage class for 5 days.

In this case, the total fee of the month is USD 45.8628, as shown in the following table.

Operation

Billable item

Code

Unit price

Billable amount

Fee

Store 1,000 GiB of data in the Standard storage class for 14 days

Storage Usage of General-purpose NAS File System (Capacity/Performance)

VolumeSize

USD 0.06 per GiB-month

1,000 GiB stored for 14 days

USD 28

Store 1,000 GiB of data in the IA storage class for 16 days

Storage Usage of IA Storage Class

VolumeIASize

USD 0.02322 per GiB-month

1,000 GiB stored for 16 days

USD 12.384

Store 1,000 GiB of data in the Archive storage class for 5 days

Storage Usage of Archive Storage Class

VolumeArchiveSize

USD 0.0076 per GiB-month

1,000 GiB stored for 5 days

USD 1.267

Delete 1,000 GiB of data after the data is stored in the Archive storage class for 5 days

Storage Usage of Archive Data Retained for Less Than 60 Days

ArchivePenaltyQuantity

USD 0.0076 per GiB-month

1,000 GiB stored for 16 days4

USD 4.0533

Dump 1,000 GiB of data from the Standard storage class to the IA storage class

Storage Usage of General-purpose NAS File System (Capacity/Performance)

VolumeSize

USD 0.06 per GiB-month

1,000 GiB stored for 1 hour5

USD 0.083

Storage Usage of IA Storage Class

VolumeIASize

USD 0.02322 per GiB-month

1,000 GiB stored for 1 hour5

USD 0.03225

Dump 1,000 GiB of data from the IA storage class to the Archive storage class

Storage Usage of IA Storage Class

VolumeIASize

USD 0.02322 per GiB-month

1,000 GiB stored for 1 hour5

USD 0.03225

Storage Usage of Archive Storage Class

VolumeArchiveSize

USD 0.0076 per GiB-month

1,000 GiB stored for 1 hour5

USD 0.011

4 The minimum storage duration of the Archive storage class is 60 days. The minimum storage duration starts from the time when a file is accessed, which is indicated by the atime parameter. Therefore, you are charged for the storage usage of archive data that is stored for 16 days (60 - 14 - 25 - 5).

5 When files are being dumped, each file has a replica in the storage space of the original storage class and the new storage class. After the files are dumped, the file replicas in the original storage class are deleted. In this case, traffic fees are incurred for the file replicas.

References

  • By default, the data of General-purpose NAS file systems is stored in the Standard storage class. You can convert the storage class of files from Standard to IA or Archive to reduce storage costs. For more information, see Manage lifecycle policies.

  • You can view the storage usage of the IA storage class, the Archive storage class, and the recycle bin. For more information, see View the storage usage of a file system.

  • You can view storage usage of the Standard, IA, and Archive storage classes of a General-purpose NAS file system in real time. For more information, see View the capacity monitoring data of a NAS file system.

  • You can create an alert rule to monitor the storage usage of a NAS file system. For more information, see Configure a basic alert rule.

  • You can view the usage details of a NAS file system. For more information, see Resource usage and bills.

FAQ

For more information about the billing of NAS, see Billing FAQ.