When can I enable the lifecycle management feature?

If the files in a General-purpose NAS file system are accessed less than twice per month, you can enable the lifecycle management feature. After you enable the feature, the files that meet a specified lifecycle management policy are automatically dumped to an Infrequent Access (IA) storage media. This way, you are billed for the files at a lower price.

Why am I unable to configure lifecycle management policies for my file system?

If your General-purpose NAS file system was created before June 1, 2020, you cannot enable the lifecycle management feature or configure lifecycle management policies for the file system. The lifecycle management feature is unavailable for General-purpose NAS file systems that use the Server Message Block (SMB) protocol or whose data encryption feature is enabled. In the Product Announcement section of the NAS console, you can view the latest information about the lifecycle management feature.

How do I configure lifecycle management polices?

To configure lifecycle management policies, you can use the NAS console or OpenAPI Explorer. For more information, see Manage a lifecycle management policy and API reference for lifecycle management policies.

When is a file dumped to an IA storage medium?

A file is dumped to an IA storage medium only if the file meets the following conditions:
  • A lifecycle management policy is configured for the directory where the file resides.
  • The size of the file is at least 64 KB.
  • The file is not accessed during the period of time that is specified in the lifecycle management policy.
    When you create a lifecycle management policy, you can specify a rule to dump the files that are not accessed in the last 14 days, 30 days, 60 days, or 90 days to an IA storage medium. The lifecycle management feature checks whether a file is infrequently accessed based on the atime parameter, which indicates the time when the file was last accessed.
    • The following operations update the atime of a file:
      • Read data from the file.
      • Write data to the file.
    • The following operations do not update the atime of a file:
      • Rename the file.
      • Modify the user, group, mode, or other attributes of the file.

What happens if I configure multiple lifecycle management policies for a single directory?

The files in the directory are dumped to an IA storage medium if the files meet a rule in one of the lifecycle management policies.

What happens if I configure two different lifecycle management policies for a directory and its subdirectory?

The files in the subdirectory are dumped to an IA storage medium based on both policies.

For example, a policy whose atime threshold is 60 days is configured for a directory and a policy whose atime threshold is 14 days is configured for the subdirectory. In this case, the files in the subdirectory that are not accessed in the last 14 days are dumped to an IA storage medium. The files in the IA storage medium are skipped when the lifecycle management feature checks for infrequently accessed files based on the policy of the parent directory.

Is a lifecycle management policy valid for all data in the specified directory?

Yes, a lifecycle management policy is valid for all data in the specified directory. If the file data in the directory meets the lifecycle management policy, the data is automatically dumped to an IA storage medium.

How long does a lifecycle management policy require to take effect?

A lifecycle management policy requires less than 2 hours to take effect. Therefore, the first file that meets the policy is dumped to the IA storage medium within 2 hours after the policy is configured.

How is the lifecycle management feature affected if a directory is renamed?

If you rename a directory for which you configure a lifecycle management policy, the lifecycle management policy no longer applies to the files in the directory. The files that are dumped to an IA storage medium remain in the IA storage medium.

If you configure a lifecycle management policy for the renamed directory, the files in the directory that meet the policy are dumped to an IA storage medium.

What happens if a lifecycle management policy is deleted?

The files in the directory for which the policy is configured are no longer dumped to an IA storage medium. The files that are dumped to the IA storage medium remain in the IA storage medium.

Are the files in a directory repeatedly dumped to an IA storage medium if a lifecycle management policy is deleted and reconfigured for the directory?

No, the files are not repeatedly dumped to the IA storage medium. After you reconfigure a lifecycle management policy, the lifecycle management feature checks for files that meet the policy. The files in the IA storage medium are skipped during the check. This prevents repeated file dumps.

Are the files in an IA storage medium accessible?

Yes, you can read data from and write data to the files in an IA storage medium the same way you read data from and write data to other files in a file system.

Which files in my file system are stored in an IA storage medium?

To query the files that are stored in an IA storage medium, you can use the NAS console or call the required API operation. For more information, see View the files stored in an IA storage medium and ListDirectoriesAndFiles.

Is the latency when you read data from and write data to a file in an IA storage medium longer than the latency when you read data from and write data a file in a Performance NAS or Capacity NAS file system?

It depends. The latency when you read data from a file in an IA storage medium for the first time may be longer than the latency when you read from a file in a NAS Performance or NAS Capacity file system. After the file is read, the latency when you read data from the file is almost the same as the latency when you read data from a file in a NAS Performance or NAS Capacity file system.

The latency when you write data to a file in an IA storage medium is almost the same as the latency when you read data from a file in a NAS Performance or NAS Capacity file system.

How am I charged if my files are dumped to an IA storage medium?

If your files are dumped to an IA storage medium, you are charged based on the billing method of the IA storage medium. For more information, see Billing of IA storage media.

Can cold data that is dumped to an IA storage medium be automatically converted to hot data after the cold data is accessed?

No, the cold data cannot be automatically converted to hot data. After cold data is dumped to an IA storage medium, the cold data is stored in the IA storage medium. If you access cold data in the IA storage medium, you are charged for the read and write traffic of the cold data. For more information, see Billing of IA storage media.

If you need to frequently access some files in the IA storage medium, we recommend that you create a data retrieval task to convert these files from cold data to hot data. For more information, see Create a data retrieval task.

How can I create a data retrieval task to retrieve files from an IA storage medium?

To create a data retrieval task, you can use the NAS console or OpenAPI Explorer. For more information, see Create a data retrieval task and CreateLifecycleRetrieveJob.

Is the read and write performance affected when a data retrieval task is running?

No, the read and write performance is not affected. You can read or write data as expected when a data retrieval task is running.

Am I charged for a data retrieval task?

Yes, you are charged for a data retrieval task. When you run a data retrieval task, the system reads data from the specified file. You are charged for reading the file from the associated IA storage medium based on the size of the file. After a data retrieval task succeeds, the file is moved to the related General-purpose NAS file system and occupies storage space. In this case, you are charged for the storage space based on the size of the file. For more information, see Billing of IA storage media.

How am I charged when I back up files that are stored in an IA storage medium?

If you use Hybrid Backup Recovery (HBR) to back up files that are stored in an IA storage medium of a General-purpose NAS file system, you are charged for using HBR resources. For more information, see Billing methods and billable items.

During the backup process, HBR reads data from the files. Therefore, you are also charged for the traffic that is generated when HBR accesses the IA storage medium. For more information, see Billing of IA storage media.