If you enable the lifecycle management feature for a General-purpose NAS file system, data that meets the specified lifecycle management rules is dumped to an Infrequent Access (IA) storage medium. You are charged for the used space of the IA storage medium and read and write traffic. The lifecycle management feature helps you reduce costs for using NAS file systems. This topic describes the billing method of General-purpose NAS file systems for which the lifecycle management feature is enabled.

Billable items

Note IA storage media cannot be separately purchased. For more information, see IA storage media.
Billable item Description
Storage usage The usage of a General-purpose NAS file system and the usage of an IA storage medium. Fees are calculated based on the maximum used storage per hour.
  • The used storage space is the total size of all files in a 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 space of the file is rounded up to 4 KiB. If the size of a file is larger than 4 KiB, the billed storage space is rounded up to the nearest multiple of 4 KiB. For example, if the size of a file is 2 KiB, the system counts the size of the file as 4 KiB. If the size of a file is 6KiB, the system counts the size of the file as 8 KiB.
  • File holes occupy storage space in a NAS file system. You are charged for the file holes in your NAS file system. A file hole consists of zeros that are not written to a file. You can create a file hole by using the truncate, lseek, or fallocate command.
  • 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. For example, after 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. After you delete a file from an IA storage medium, you are charged for the file based on the unit price of storage space in the IA storage medium. For more information, see Enable a recycle bin.
Read and write traffic Traffic fees are incurred when the data in an IA storage medium 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 subsequent hours.
  • If the data in the file system meets the lifecycle management rules, the data is automatically dumped to the IA storage medium. No write traffic fees are incurred for the data transfer.
  • If you access files in an IA storage medium, you are charged for the actual read and write traffic. If you read only a part of a file, you are charged for the read traffic that is generated.
  • 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 an IA storage medium, you are charged for read traffic based on the size of the files.
  • You are not charged for managing metadata in the IA storage medium. For example, you are not charged for running the ls command to show the metadata of specified files.

Billing cycle

The fees for each hour are deducted from your account balance the next hour. For example, you are billed at 09:30 for the fees that are incurred from 08:00 to 09:00.

Note If you receive a bill at 09:30, the bill may include fees that are incurred from 07:00 to 08:00 due to system latency.

Comparison of billing methods

After you create an Apsara File Storage NAS file system, you are billed based on the pay-as-you-go billing method by default. You can purchase resource plans and storage capacity units (SCUs) to offset fees. The following table compares the operations and billable items that are supported by each billing method. A check (✓) sign indicates that the operation is supported by the billing method. A cross (×) sign indicates that the operation is not supported by the billing method. A hyphen (-) sign indicates that the operation is not applicable to the billing method.
Billing method Billable item Purchase Offset the storage usage fees of General-purpose NAS file systems of different storage classes Offset the storage usage fees of multiple NAS file systems Offset only the storage usage fees of NAS file systems Renew Upgrade Purchase multiple at a time
Pay-as-you-go All billable items of NAS file systems - - - - - - -
Resource plan
  • Storage usage of General-purpose NAS file systems
  • Storage usage of IA storage media
Yes
Storage plan
  • Storage usage of General-purpose NAS file systems
  • Storage usage of IA storage media
× × × ×
SCU Storage usage of General-purpose NAS file systems × × ×
If you have resource plans, SCUs, and storage plans associated with your Alibaba Cloud account, the storage usage fees are offset in the following order: storage plans, resource planes, and then you are charged based on the pay-as-you-go billing method.

Billing methods

  • Pay-as-you-go

    After you create an Apsara File Storage NAS file system, you are billed based on the pay-as-you-go billing method by default.

    The storage usage fee in a billing cycle is calculated by using the following formula: Storage usage fee = Storage usage fee of a General-purpose NAS file system + Storage usage fee of an IA storage medium + Traffic fee of the IA storage medium = Maximum storage usage of a General-purpose NAS file system per hour × Unit price per hour + Maximum storage usage of an IA storage medium per hour × Unit price per hour + Amount of read traffic × Unit price per hour + Amount of write traffic × Unit price per hour
    Note
    • If the lifecycle management feature is enabled, the storage usage of the General-purpose NAS file system is a storage space. This storage space is occupied by the data that is not dumped to an IA storage medium.
    • You can log on to the NAS console to view the storage usage in the Basic Information section. The storage usage is updated once per hour. Due to latency, the storage usage displayed in the console at the current local time may be the storage usage of the previous hour.
    • General-purpose NAS file systems are divided into two types: Capacity NAS file system and Performance NAS file system. Both types have different unit prices for storage usage. For NAS file systems, the unit of storage usage fee is USD/GiB/month. When the storage usage fee is calculated, the unit of measurement is converted to USD/GiB /hour. For more information, see Apsara File Storage NAS pricing.
  • Resource plans (recommended)

    A resource plan can be used to reduce the cost of resources. You can purchase multiple resource plans at the same time and use them to offset the storage usage fees of multiple file systems. Resource plans are applied based on the following order: Performance NAS file systems, Capacity NAS file systems, and IA storage media.

    • Purchase method

      For more information about how to purchase a storage plan, see Manage storage plans.

    • Deduction rules
      The following table describes rules that apply when you use resource plans to offset the storage usage of different storage classes of NAS file systems in mainland China. To learn how rules are applied in other regions, you can use the calculator feature to view the relevant information.
      Storage class Conversion coefficient Description
      Capacity NAS file system 1 You can use 1 GiB of base capacity in your General-purpose resource plan to offset 1 GiB of storage usage from a Capacity NAS file system.
      Performance NAS file system 5.47 You can use 5.47 GiB of base capacity in your General-purpose resource plan to offset 1 GiB of storage usage from a Performance NAS file system.
      IA storage medium 0.37 You can use 0.37 GiB of base capacity in your General-purpose resource plan to offset 1 GiB of storage usage from an IA storage medium.
      You can use the calculator feature provided by Alibaba Cloud to calculate the deductions of the resource plans within your account in the current region. This way, you can select appropriate resource plans based on the current storage usage to reduce your costs.
    • Renewal and upgrade

      You can renew and upgrade a resource plan. For more information, see Manage resource plans.

  • SCUs

    An SCU is a type of subscription billing method. You can purchase multiple SCUs at the same time and use them to offset the storage usage fees of multiple Alibaba Cloud storage services. SCUs are more flexible and cost-effective than storage plans that are dedicated to specific storage services.

    • Purchase method

      For more information about how to purchase SCUs, see Create an SCU.

    • Deduction rules
      You can use SCUs to offset the storage usage fees of NAS, OSS, and ECS resources. The following table describes the rules that apply when you use SCUs to offset the storage usage fees of different storage classes of NAS file system in mainland China. For more information about the rules for other Alibaba Cloud storage services and regions, visit the Pricing page.
      File system type Deduction factor Description
      Capacity NAS file system 0.25 You can use 0.25 GB of capacity in your SCU to offset 1 GB of storage usage from a Capacity NAS file system.
      Performance NAS file system 0.889 You can use 0.889 GB of capacity in your SCU to offset 1 GB of storage usage from a Performance NAS file system.
  • Storage plans

    A storage plan is a type of subscription billing method. You can use a storage plan to offset only the storage usage fees of a file system to which the storage plan is attached.

    Notice Alibaba Cloud supports resource plans for Apsara File Storage NAS. You can no longer purchase storage plans. However, you can renew or upgrade existing storage plans. Compared with a storage plan, a resource plan does not need to be bound to a file system. You can purchase multiple resource plans to offset the storage usage fees of multiple file systems.
    • Offset rules
      • A storage plan is used to first offset the storage usage fee of General-purpose NAS file systems. If the storage plan still has a positive balance, the storage plan is used to offset the storage usage fee of an IA storage medium based on a specific coefficient.
        • If the following condition is met, the storage plan is sufficient to offset the storage usage fee of the IA storage medium. (Capacity of the storage plan - Storage usage of the General-purpose NAS file system) × Coefficient - Storage usage of the IA storage medium ≥ 0 GiB.
        • If the following condition is met, the storage plan is insufficient to offset the storage usage fee of the IA storage medium. (Capacity of the storage plan - Storage usage of the General-purpose NAS file system) × Coefficient - Storage usage of the IA storage medium < 0 GiB. The fees for the excess storage usage are calculated based on the pay-as-you-go billing method.

          The coefficient in the preceding formulas varies based on the type of the file system. For Performance NAS file systems, the coefficient is 12.333. For Capacity NAS file systems, the coefficient is 2.333.

      • You can attach only one storage plan to a General-purpose NAS file system at a time. If you delete a General-purpose NAS file system, its storage plan is automatically detached. However, the detached storage plan can be attached to another file system of the same type in the same region to offset the storage usage fee of the file system.
    • Renewal and upgrade

      You can renew and upgrade a storage plan. For more information, see Manage storage plans.

Examples

Example 1: Mr. Zhang has created a Performance NAS file system named File System A in the China (Beijing) region. The storage usage of File System A in January 2021 is 100 GiB per hour. In the storage usage, 10 GiB of data is stored in a General-purpose NAS file system, and 90 GiB of data is stored in an IA storage medium. The read traffic of the IA storage medium is 1 GiB and the write traffic of the IA storage medium is 2 GiB within the month. The following table lists the fees that are incurred by File System A within the month based on storage plans and the pay-as-you-go billing method.
Billing method Billing
Pay-as-you-go
  • Storage usage fee of General-purpose NAS file system = 10 GiB × USD 0.3/GiB/month = USD 3
  • Storage usage fee of the IA storage medium = 90 GiB × USD 0.02322/GiB/month = USD 2.0898
  • Read and write traffic fees of the IA storage medium
    • Read traffic fee = 1 GiB × USD 0.00929/GiB = USD 0.00929
    • Write traffic fee = 2 GiB × USD 0.00929/GiB = USD 0.01858
Total fee = USD 3 + USD 2.0898 + USD 0.00929 + USD 0.01858 = USD 5.11767
Resource plan for General-purpose NAS file systems (100 GiB, one month) The 100 GiB of storage capacity in the resource plan is used to first offset 10 GiB of storage usage from the Performance NAS file system. The remaining storage capacity of the resource plan is calculated by using the following equation: 100 GiB - 10 GiB × 5.47 = 45.3 GiB.

The 45.3 GB of storage capacity is then used to offset 90 GiB of storage usage from the IA storage medium. The remaining storage capacity of the resource plan is calculated by using the following equation: 45.3 GiB - 90 GiB × 0.37 =12 GiB.

Only the pay-as-you-go billing method can be used to calculate the read and write traffic fees of IA storage media.
  • Read traffic fee = 1 GiB × USD 0.00929/GiB = USD 0.00929
  • Write traffic fee = 2 GiB × USD 0.00929/GiB = USD 0.01858

Total fee = USD 4.57 + USD 0.00929 + USD 0.01858 = USD 4.59787

USD 4.57 is the fee of a resource plan (100 GiB, one month) for a General-purpose NAS file system in the China (Beijing) region.

Example 2: Mr. Zhang has created a Performance NAS file system named File System A in the China (Beijing) region. The storage usage of File System A in January 2021 is 210 GiB per hour. In the storage usage, 10 GiB of data is stored in a General-purpose NAS file system and 200 GiB of data is stored in an IA storage medium. The read traffic of the IA storage medium is 1 GiB, and the write traffic of the IA storage medium is 2 GiB within the month. Mr. Zhang also has a Capacity NAS file system named File System B. The storage usage of File System B in January 2021 is 90 GiB per hour. The following table lists the fees that are incurred by File System A and File System B within the month based on storage plans and the pay-as-you-go billing method.
Billing method Billing
Pay-as-you-go
  • Storage usage fees of the General-purpose NAS file system
    • Storage usage fee of the Performance NAS file system = 10 GiB × USD 0.3/GiB/month = USD 3
    • Storage usage fee of the Capacity NAS file system = 90 GiB × USD 0.06/GiB/month = USD 5.4.
  • Storage usage fee of the IA storage medium = 200 GiB × USD 0.02322/GiB/month = USD 4.644
  • Read and write traffic fees
    • Read traffic fee = 1 GiB × USD 0.00929/GiB = USD 0.00929
    • Write traffic fee = 2 GiB × USD 0.00929/GiB = USD 0.01858
Total fee = USD 3 + USD 5.4 + USD 4.644 + USD 0.00929 + USD 0.01858 = USD 13.07187
Two resource plans for General-purpose NAS file systems (100 GiB, one month) The 100 GiB of storage capacity in the resource plans is used to first offset 10 GiB of storage usage from the Performance NAS file system. The remaining storage capacity of the resource plan is calculated by using the following equation: 200 GiB - 10 GiB × 5.47 = 145.3 GiB. The 145.3 GiB of storage capacity is then used to offset 90 GiB of storage usage from the IA storage medium. The remaining storage capacity of the resource plan is calculated by using the following equation: 145.3 GiB - 90 GiB × 1 = 55.3 GiB.

The 55.3 GiB of storage capacity is then used to offset 149.5 GiB of storage usage from the IA storage medium (55.3 GiB/0.37 ≈ 149.5 GiB). The excess storage usage of the IA storage medium is 50.5 GiB (200 GiB - 149.5 GiB = 50.5 GiB) is calculated based on the pay-as-you-go billing method by using the following equation: 50.5 GiB × USD 0.02322 = USD 1.17261.

Only the pay-as-you-go billing method can be used to calculate the read and write traffic fees of IA storage media.
  • Read traffic fee = 1 GiB × USD 0.00929/GiB = USD 0.00929
  • Write traffic fee = 2 GiB × USD 0.00929/GiB = USD 0.01858

Total fee = USD 4.57 × 2 + USD 1.17261 + USD 0.00929 + USD 0.01858 = USD 10.34048

USD 4.57 is the fee of a resource plan (100 GiB, one month) for a General-purpose NAS file system in the China (Beijing) region.

Example 3: Mr. Zhang has created a Capacity NAS file system named File System A in the China (Beijing) region. The storage usage of File System A in January 2021 is 1000 GiB per hour. In the storage usage, 200 GiB of data is stored in a General-purpose NAS file system, and 800 GiB of data is stored in an IA storage medium. The read traffic in the IA storage medium is 1 GiB and the write traffic in the IA storage medium is 2 GiB within the month. The following table lists the fees that are incurred by File System A within the month based on storage plans and the pay-as-you-go billing method.
Billing method Billing
Pay-as-you-go
  • Storage usage fee of the General-purpose NAS file system: 200 GiB × USD 0.06/GiB/month = USD 12
  • Storage usage fee of the IA storage medium = 800 GiB × USD 0.02322/GiB/month = USD 18.576
  • Read and write traffic fees
    • Read traffic fee = 1 GiB × USD 0.00929/GiB = USD 0.00929
    • Write traffic fee = 2 GiB × USD 0.00929/GiB = USD 0.01858
Total fee = USD 12 + USD 18.576 + USD 0.00929 + USD 0.01858 = USD 30.60387
Storage plan (500 GiB, one month) The 500 GiB of storage capacity in the resource plan is used to first offset 200 GiB of storage usage from the Capacity NAS file system. The remaining capacity of the resource plan is calculated by using the following equation: 500 GiB - 200 GiB = 300 GiB.

The 300 GiB of storage capacity is then used to offset 699.9 GiB of storage usage from the IA storage medium (300 GiB × 2.333 = 699.9 GiB). The excess storage usage of the IA storage medium is 100.1 GiB (800 GiB - 699.9 GiB = 100.1 GiB). The fee for this storage usage is calculated based on the pay-as-you-go billing method by using the following equation: 100.1 GiB × USD 0.02322 = USD 2.324322.

Only the pay-as-you-go billing method can be used to calculate the read and write traffic fees of IA storage media.
  • Read traffic = 1 GiB × USD 0.00929/GiB = USD 0.00929
  • Write traffic = 2 GiB × USD 0.00929/GiB = USD 0.01858

Storage usage fee = USD 22.85 + USD 2.324322 + USD 0.00929 + USD 0.01858 = USD 25.202192

USD 22.85 is the fee of a storage plan (500 GiB, one month) for a Capacity NAS file system in the China (Beijing) region.

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