File Storage NAS:Billing for General-purpose NAS

Base fees

To check your General-purpose NAS usage, see Query file system resource usage or Resource usage and bills.

Additional fees

Fees incurred when you enable and use lifecycle management (Infrequent Access and Archive Storage) or the recycle bin feature.

Enabling the recycle bin or lifecycle management may cause your billable storage usage to exceed your actual stored data. To view detailed usage for these storage types, see View file system details or Query General-purpose NAS usage details.

• Note ①: Storage capacity

  • Storage capacity is the total size of all files (excluding directories). Files smaller than 4 KiB are billed as 4 KiB. Files larger than 4 KiB are rounded up to the nearest multiple of 4 KiB. For example, a 2 KiB file counts as 4 KiB; a 6 KiB file counts as 8 KiB.

  • Sparse regions (unwritten space within a file, often created by commands like truncate, lseek, or fallocate) count toward storage capacity and incur charges.

  • General-purpose NAS stores data in Standard storage by default. When you change the storage class, files are converted in batches for performance. During conversion, copies exist in both the source and target storage classes, temporarily increasing billable usage. Billing returns to normal after conversion completes.

• Note ②: Read/write traffic

  • Data automatically moved to IA or Archive Storage based on lifecycle rules incurs no write traffic fees.

  • Accessing files in IA or Archive Storage incurs fees based on actual read/write traffic. Partial reads are billed only for the accessed portion.

  • IA or Archive read/write traffic fees apply regardless of network environment—any read or write operation generates charges.

  • Data retrieval tasks incur read traffic fees based on the target file size.

  • Backing up files from IA or Archive Storage incurs read traffic fees based on the target file size.

  • Security services (such as Security Center anti-ransomware scans) reading files from IA or Archive Storage incur read traffic fees based on actual traffic.

  • Metadata operations on IA or Archive files are free. For example, running the ls command on file metadata.

After changing storage classes and using resource plans, costs are:

Note ③: Equivalent base capacity

NAS resource plans apply offset factors based on file system type, storage class, and region. Calculate accordingly when purchasing. For details, see Offset factor.

Comparison shows:

• For Capacity file systems, changing storage classes and using resource plans saves 23.83%.

• For Advanced file systems, changing storage classes and using resource plans saves 64.85%.

• For Performance file systems, changing storage classes and using resource plans saves 69.53%.

Example 1: Shared storage for web services

On November 1, 2024, Mr. Wang deployed a shared-storage web service in a Capacity file system in China (Hangzhou), using 500 GiB of storage per hour. His total monthly cost is approximately USD 30. Billing details:

Example 2: Accessing infrequently accessed data

Mr. Zhang created a Performance NAS file system in China (Hangzhou). In November 2024, he used 100 GiB of storage per hour: 10 GiB in Standard storage and 90 GiB in IA storage. He also read 1 GiB and wrote 2 GiB to IA storage that month. His total monthly cost is approximately USD 5.11767. Billing details:

Example 3: Cross-region disaster recovery

On November 1, 2024, Mr. Zhang stored 150 GiB of files in a Performance file system (System A) in China (Beijing). To improve data security and reliability against single-region failures, he set up a cross-region backup policy. This ensures business continuity—even if a region suffers natural disasters or power outages, he can restore data from the backup vault to create System B. His total monthly cost is approximately USD 59.5418. Billing details:

^③ Cloud Backup applies deduplication and compression, so billing is based on the reduced capacity.

Example 4: Automatic data tiering and cleanup

On November 1, 2024, Mr. Zhang used 1,000 GiB of storage per hour in a Capacity file system in China (Beijing). All files were under the /mnt directory. He configured the following lifecycle rules:

1. Phase 1: Data requires frequent access. All files under /mnt use Standard storage for 14 days.

2. Phase 2: Files are accessed less than once every 14 days. All files under /mnt move to IA storage for 16 days.

3. Phase 3: Data enters a phase where it is accessed less than once every 30 days, and all files in the /mnt folder are dumped to Archive Storage. This phase lasts for 5 days.

4. Phase 4: Data is no longer needed. After 5 days in Archive Storage, delete all files under /mnt.

His total monthly cost is USD 55.7425. Billing details:

^④ Archive Storage has a minimum storage duration of 60 days. The start time for this minimum duration is calculated from the later of the file dump time and the file modification time (mtime). If you modify an archived file within 24 hours, you incur storage capacity charges for Archive Storage with a duration shorter than 60 days only once, and modifying the archived file resets the 60-day timer. Therefore, in this scenario, storage capacity charges apply for 55 days (that is, 60 − 5) of Archive Storage under the 60-day minimum.

^⑤ During storage class transitions, copies exist in both source and target classes until deletion completes. Both copies incur fees.

Example 5: Accessing archived data

Mr. Zhang created a Performance NAS file system in China (Hangzhou) with 100 GiB of data. He set a lifecycle rule to move data to Archive Storage after 30 days. At day 60, he overwrote 1 GiB, then reduced the size back to 100 GiB, wrote another 2 GiB, and finally deleted down to 101 GiB. At day 90, he deleted the data. His total cost is approximately USD 33.10626. Billing details:

^④ Archive Storage has a minimum storage duration of 60 days. This minimum duration is calculated from the later of the file dump time and the file modification time (mtime). If you modify an archived file within 24 hours and its storage duration is less than 60 days, you incur storage capacity charges for the under-minimum duration only once. Modifying an archived file resets the 60-day calculation period. Therefore, in this scenario, two separate 30-day periods—that is, (60 − 30) days each—of Archive Storage with durations shorter than 60 days will each incur storage capacity charges.

• First 30-day scenario: On day 60, you perform overwrite and data deletion operations. Because these modifications and writes occur within 24 hours, you incur only one storage capacity charge for Archive Storage with a duration shorter than 60 days. The billable hours for Archive Storage are then reset.

• Second 30-day scenario: On day 90, the data was deleted.

^⑤ During storage class transitions, copies exist in both source and target classes until deletion completes. Both copies incur fees.