Lifecycle management FAQ-File Storage NAS(NAS)-阿里云帮助中心

When should I use lifecycle management?

If files in your file system are accessed one to three times per month, we recommend that you use lifecycle management to configure a policy that transitions these files to Infrequent Access (IA) storage. You are then billed based on the rates for the IA storage class.
If files in your file system are accessed once or twice per quarter, we recommend that you use lifecycle management to configure a policy that transitions these files to Archive storage. You are then billed based on the rates for the Archive storage class.

To further reduce storage costs, you can configure policies for both Infrequent Access (IA) storage and Archive storage for the same file system. If a file meets the conditions of multiple policies, NAS applies the policy that results in the lowest cost. For more information, see lifecycle management.

Why does my file system not support lifecycle management?

File systems with data encryption enabled do not support lifecycle management.

How do I configure a lifecycle management policy?

You can configure a lifecycle management policy in the NAS console or by calling an API operation. For more information, see Manage a lifecycle policy and Lifecycle management API reference.

Choosing a policy and directory

To help you choose the right lifecycle management policy and directory, NAS provides the NAS data tiering analysis tool. You can use this tool to scan a specified directory and its subdirectories. The tool then lists subdirectories in descending order based on the amount of cold data they contain. This analysis helps you decide which directories to apply policies to based on the amount of cold data. For more information, see the User guide.

File transition eligibility

A file must meet the following three conditions to be transitioned to a lower-cost storage class:

A lifecycle management policy is configured for the directory where the file is stored.
The file size is between 64 KiB and 4.88 TiB.
The file's last access time meets the criteria of the lifecycle management policy.

When you create a lifecycle management policy, you can configure a rule to transition files that have not been accessed for more than 14, 30, 60, or 90 days to Infrequent Access (IA) storage. You can also configure a rule to transition files that have not been accessed for more than 14, 30, 60, 90, or 180 days to Archive storage. Lifecycle management determines this based on the file's access time (atime).
- The atime is updated by the following operations:
  - Reading a file
  - Writing to a file
- The atime is not updated by the following operations:
  - Renaming a file
  - Modifying file attributes, such as the user, group, or mode

Multiple policies on a single directory

If a directory has multiple lifecycle management policies and a file meets the criteria for more than one policy, NAS applies the policy that results in the lowest cost.

Policy precedence in nested directories

If a file meets the criteria of any applicable policy, NAS applies the policy that results in the lowest cost.

For example, a policy is configured for the current directory to transition files to Infrequent Access (IA) storage after 14 days of inactivity. A different policy is configured for its parent or a higher-level directory to transition files to IA storage after 60 days of inactivity. In this case, files in the current directory that have not been accessed for 14 days are transitioned to IA storage. When the parent directory's policy runs, it skips the files that have already been transitioned.

Policy scope

Yes. All files in the target directory that meet the lifecycle management policy criteria are automatically transitioned to Infrequent Access (IA) storage or Archive storage.

Transition time

The transition time depends on the size of the file system and the amount of data to be transitioned. After you enable the feature, the first transition of files that meet the policy criteria can be completed in as little as 2 hours, but typically within 24 hours. Subsequent transitions are completed on a weekly schedule.

Effect of renaming a directory

If you rename a directory that is associated with a lifecycle management policy, the policy no longer applies to the files in that directory. Files that have already been transitioned to Infrequent Access (IA) storage or Archive storage remain in their current storage class.

If you configure a new lifecycle management policy for the renamed directory, that policy takes effect. Files in the directory that meet the new policy's criteria are transitioned to the appropriate storage class.

Effect of deleting a policy

If you delete a lifecycle management policy, files in the associated directory are no longer transitioned to Infrequent Access (IA) storage or Archive storage. Files that have already been transitioned remain in their current storage class.

Re-creating a policy

No. When you re-create a lifecycle management policy, its check mechanism automatically skips files that have already been transitioned to Infrequent Access (IA) storage or Archive storage, preventing them from being transitioned again.

Read/write access to transitioned files

Yes. You can read from and write to files in Infrequent Access (IA) storage or Archive storage just like any other file in the file system. For more information about the performance of different storage classes, see Storage class comparison.

Viewing transitioned files

You can query for files stored in Infrequent Access (IA) storage or Archive storage by using the NAS console or by calling the ListDirectoriesAndFiles API operation. For more information, see View the files stored in the IA or Archive storage class and ListDirectoriesAndFiles.

Read/write latency for IA storage

The first time you read a file from Infrequent Access (IA) storage, you may experience higher latency. However, subsequent reads of that file within a short period have latency comparable to reading a file in Standard storage on a Performance, Premium, or Capacity General-purpose NAS file system.

The latency for writing to a file in IA storage is nearly identical to writing to a file in Standard storage on a Performance, Premium, or Capacity General-purpose NAS file system. For more information about the performance of different storage classes, see Storage class comparison.

Read/write latency for Archive storage

The first time you read a file from Archive storage, you may experience higher latency. However, subsequent reads of that file within a short period have latency comparable to reading a file in Standard storage on a Performance, Premium, or Capacity General-purpose NAS file system.

The latency for writing to a file in Archive storage is nearly identical to writing to a file in Standard storage on a Performance, Premium, or Capacity General-purpose NAS file system. For more information about the performance of different storage classes, see Storage class comparison.

Billing for IA storage

When files are transitioned to Infrequent Access (IA) storage, you are charged based on the billing method for the IA storage class. For more information, see Billing for General-purpose NAS.

Billing for Archive storage

When files are transitioned to Archive storage, you are charged based on the billing method for the Archive storage class. The minimum storage duration for Archive storage is 60 days. If a file is deleted, retrieved, or reduced in size before it has been stored for 60 days (1,440 hours), you are charged a storage fee for the remaining duration (1,440 hours minus the actual storage duration) based on the file's original size.

The minimum storage duration starts from the later of two timestamps: the time the file was transitioned, or the file's last modification time (mtime). Any early deletion fee is charged only once within a 24-hour period. If you modify an archived file, the 60-day minimum storage duration timer resets. For more information, see Billing for General-purpose NAS.

Early removal fees from Archive storage

The minimum storage duration for Archive storage is 60 days. If a file is deleted, retrieved, or reduced in size before it has been stored for 60 days (1,440 hours), you are charged a storage fee for the remaining duration (1,440 hours minus the actual storage duration) based on the file's original size.

The minimum storage duration starts from the later of two timestamps: the time the file was transitioned, or the file's last modification time (mtime). Any early deletion fee is charged only once within a 24-hour period. If you modify an archived file, the 60-day minimum storage duration timer resets. For more information, see Billing for General-purpose NAS.

Example	Fees incurred
A file is stored in Standard storage for 14 days, then transitioned to Archive storage by a lifecycle management policy. After 40 days in Archive storage, the file is deleted.	Storage fee for 14 days in Standard storage Storage fee for 40 days in Archive storage Early deletion charge for the remaining 20 days of the 60-day minimum Data copy fee for changing the storage class
A file is stored in Standard storage for 14 days, then transitioned to Archive storage. After 50 days in Archive storage, it is retrieved back to Standard storage.	Storage fee for 14 days in Standard storage Storage fee for 50 days in Archive storage Early retrieval charge for the remaining 10 days of the 60-day minimum Archive storage read traffic fee for the data retrieval task Data copy fee for changing the storage class
A 100 GiB file is in Standard storage for 14 days, then transitioned to Archive storage. After 5 days, the file is modified to 105 GiB. After another 20 days in Archive storage, the file is deleted.	Storage fee for 100 GiB in Standard storage for 14 days Storage fee for 100 GiB in Archive storage for 5 days Early deletion charge for the original 100 GiB for the remaining 55 days Storage fee for 105 GiB in Archive storage for 20 days Early deletion charge for the modified 105 GiB for the remaining 40 days Archive storage write traffic fee for the 10 GiB data modification Data copy fee for changing the storage class

Data promotion from IA storage

No. Once data is transitioned to Infrequent Access (IA) storage, it remains there. Accessing this cold data incurs read/write traffic fees for IA storage. For more information, see Billing for General-purpose NAS.

If you need to frequently access data that is in IA storage, create a data retrieval task to restore the specified files or directories to Standard storage. Running a data retrieval task reads the target data and incurs read traffic fees. For more information, see Create a data retrieval task.

Data promotion from Archive storage

No. Once data is transitioned to Archive storage, it remains there. Accessing this cold data incurs read/write traffic fees for Archive storage. For more information, see Billing for General-purpose NAS.

If you need to frequently access data in Archive storage, create a data retrieval task to restore the specified files or directories to Standard storage. Running a data retrieval task reads the target data and incurs read traffic fees. For more information, see Create a data retrieval task.

Creating a retrieval task for IA storage

You can create a data retrieval task by using the NAS console or by calling the CreateLifecycleRetrieveJob API operation. For more information, see Create a data retrieval task or CreateLifecycleRetrieveJob.

Creating a retrieval task for Archive storage

You can create a data retrieval task by using the NAS console or by calling the CreateLifecycleRetrieveJob API operation. For more information, see Create a data retrieval task or CreateLifecycleRetrieveJob.

Effect of retrieval tasks on performance

No. You can read and write data normally while a data retrieval task is running.

Charges for data retrieval tasks

Yes. When a data retrieval task runs, it reads data from the target files. This incurs a read traffic fee based on the file size and its current storage class (Infrequent Access (IA) storage or Archive storage). After the task is complete, the files are restored to Standard storage and incur storage capacity fees for the General-purpose NAS file system. For more information, see Billing for General-purpose NAS.

Billing for backing up transitioned files

When you use Cloud Backup to back up files from the Infrequent Access (IA) storage or Archive storage of a General-purpose NAS file system, Cloud Backup charges you service fees. For more information, see Billing methods and billable items.

To back up files, the Cloud Backup service must read data from the files. This action incurs read traffic fees for IA storage or Archive storage, which appear on your NAS bill. For more information, see Billing for General-purpose NAS.

How do I disable lifecycle management?

Lifecycle management allows you to transition infrequently accessed cold data in a General-purpose NAS file system to lower-cost storage classes such as Infrequent Access (IA) storage or Archive storage.

If you no longer want to use this feature, follow these steps to disable it:

Log on to the NAS console.
In the left-side navigation pane, choose Lifecycle Management > Lifecycle Policies.
In the top navigation bar, select the resource group and region where your file system resides.
In the policy list, find the policy you want to remove and click Delete in its Delete column. Then, follow the on-screen instructions.

After you delete the policy, files that match its criteria are no longer transitioned to Infrequent Access (IA) storage or Archive storage. However, files that were already transitioned remain in their current storage class and continue to incur storage fees for that class.

If you want to move data from Infrequent Access (IA) storage or Archive storage back to Standard storage, see Create a data retrieval task.