When can I enable the lifecycle management feature?
If the files in a General-purpose NAS file system are accessed less than twice a month, we recommend that you enable the lifecycle management feature. After you enable the feature, the files that meet a specified lifecycle policy are automatically dumped to the Infrequent Access (IA) storage medium. This helps reduce storage costs.
Why am I unable to enable the lifecycle management feature 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 policies for the file system. The lifecycle management feature is unavailable for file systems for which the data encryption feature is enabled.
How do I configure lifecycle policies?
To configure lifecycle policies, you can use the NAS console or OpenAPI Explorer. For more information, see Manage a lifecycle policy and CreateLifecyclePolicy.
Which files can be dumped to the IA storage medium?
A file that meets the following conditions can be dumped to the IA storage medium:
A lifecycle policy is configured for the directory in which the file is stored.
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 policy.
When you create a lifecycle policy, you can configure a rule to dump the files that are not accessed in the previous 14 days, 30 days, 60 days, or 90 days to the IA storage medium. The lifecycle management feature checks whether a file is infrequently accessed based on the atime parameter, which specifies 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 policies for a single directory?
If the files in the directory meet a rule in one of the lifecycle policies, the files are dumped to the IA storage medium.
What happens if I configure two different lifecycle policies for a directory and its subdirectory?
The files in the subdirectory are dumped to the 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 previous 14 days are dumped to the 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 policy valid for all data in the specified directory?
Yes, if the file data in the directory meets the lifecycle policy, the data is automatically dumped to the IA storage medium.
How long does a file that matches a lifecycle policy require to be dumped to the IA storage medium?
If the lifecycle management feature is enabled, a file that meets a specified lifecycle policy is dumped to the IA storage medium in 2 to 24 hours. The time that is required to dump the file to the IA storage medium varies based on the storage usage of the file system and the size of the file. Subsequent file dumps are performed at a specific point in time every week.
What happens if I rename a directory for which a lifecycle policy is configured?
If you rename a directory for which you configure a lifecycle policy, the policy no longer takes effect on the files in the directory. The files that are dumped to the IA storage medium remain in the IA storage medium.
If you configure a lifecycle policy for the renamed directory, the files in the directory that meet the policy are dumped to the IA storage medium.
What happens if a lifecycle policy is deleted?
The files in the directory for which the policy is configured are no longer dumped to the 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 the IA storage medium if I delete the existing lifecycle policy and then reconfigure a lifecycle policy for the directory?
No, after you reconfigure a lifecycle 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 the IA storage medium accessible?
Yes, you can read data from and write data to the files in the 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 the IA storage medium?
You can query the files that are stored in the IA storage medium in the NAS console or by calling API operations. For more information, see Manage the files in the IA storage medium and ListDirectoriesAndFiles.
Is the latency when I read data from and write data to a file in the IA storage medium longer than the latency when I read data from and write data to a file in a Performance NAS or Capacity NAS file system?
It depends. The latency when you read data from a file in the IA storage medium for the first time may be longer than the latency when you read from a file in a Performance NAS or Capacity NAS 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 Performance NAS or Capacity NAS file system.
The latency when you write data to a file in the IA storage medium is almost the same as the latency when you write data to a file in a Performance NAS or Capacity NAS file system.
How am I charged if my files are dumped to the IA storage medium?
If your files are dumped to the IA storage medium, you are charged based on the billing method of the IA storage medium. For more information, see Billing of General-purpose NAS file systems.
Can cold data that is dumped to the IA storage medium be automatically converted to hot data after the cold data is accessed?
No, after cold data is dumped to the 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 General-purpose NAS file systems.
If you need to frequently access data in the IA storage medium, we recommend that you create a data retrieval task to retrieve specific files or data in a directory to a General-purpose NAS file system. If you run the data retrieval task to read the required data, you are charged for the read traffic. For more information, see Manage the files in the IA storage medium.
How do I create a data retrieval task to retrieve files from the IA storage medium?
You can create a data retrieval task in the NAS console or by using OpenAPI Explorer. For more information, see Manage the files in the IA storage medium or CreateLifecycleRetrieveJob.
Is the read or write performance of a file system affected when a data retrieval task is running?
No, the read or write performance of a file system 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 IA storage medium based on the size of the file. If a data retrieval task is successful, 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 General-purpose NAS file systems.
How am I charged when I back up files that are stored in the IA storage medium?
If you use Hybrid Backup Recovery (HBR) to back up files that are stored in the IA storage medium of a General-purpose NAS file system, you are charged for using HBR resources. For more information, see Billable items and billing methods.
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 General-purpose NAS file systems.
How do I disable the lifecycle management feature?
After you enable the lifecycle management feature, you can dump the cold data that has not been accessed for a long time from a General-purpose NAS file system to the IA storage class. The feature helps you reduce storage costs.
If you no longer want to use the lifecycle management feature, perform the following steps to disable the feature:
Log on to the NAS console.
In the left-side navigation pane, choose .
In the top navigation bar, select a region.
On the Lifecycle Policies page, find the lifecycle policy that you want to delete, and click Delete in the Actions column. In the message that appears, click OK.
After the lifecycle policy is deleted, the data that meets the lifecycle policy is no longer dumped to the IA storage class. If data has been dumped to the IA storage class before the policy is deleted, the data continues to be stored in the IA storage class. You are charged based on the storage usage of the IA storage class.
For more information about how to retrieve the data that has been dumped to the IA storage class to a General-purpose NAS file system, see Create a data retrieval task.