Convert Between Storage Classes

KS3 provides the following storage classes: Standard, IA, and Archive. You can change the storage class of an object.

You can use one of the following methods to change the storage class of an object:

• Method 1: Configure lifecycle rules to automatically change the storage class.
• Method 2: Use the console, SDK, or API to manually change the storage class.

Automatic change

You can configure lifecycle rules to automatically change the storage class in the following way:

• From Standard to IA or Archive.
• From IA to Archive.

The following figure shows the automatic change rules of storage classes

For more information about lifecycle management, see Manage your storage lifecycle.

You can configure lifecycle rules in the KS3 console. For more information, see Manage lifecycle.

Manual change

When you change the storage class of an object, the object is saved as a new object of the specified storage class and the original object is overwritten. If you change the storage class of an IA or Archive object and the storage duration is shorter than the specified minimum duration, you are charged for early deletion. For more information, see Billing modes and items.

To change the storage class of an Archive object, restore the object and wait until it is readable. For more information, see Archive.

You can use the following methods to manually change the storage class of an object:

Change the object storage class by using PUT Object Copy.

• API reference: PUT Object Copy
• SDK reference: Use the SDK for Java to change the storage class of an object
• Console operation: Change the storage class of an object

More SDKs will support this operation.

Usage notes

After the storage class of an object is changed, the storage fees are calculated based on the unit price of the new storage class. If you want to change the storage class of an object to IA or Archive, take note of the following items:

• Minimum storage period

  The minimum storage period is 30 days for an IA object, and 90 days for an Archive object. If you delete these objects in advance, you still need to pay the storage cost for the remaining days of the minimum storage period.

  If you manually change the storage class of an object, the storage period will be reset to 0. For example, an object named test.txt has been stored as a Standard object in KS3 for 10 days. If you manually change the storage class of this object to IA, the new object must be stored for 30 days to meet the requirement of the minimum storage duration of 30 days.

• Restoration time of Archive objects

  It takes 1 to 10 minutes to restore Archive objects to the readable state. If your business needs to read data in real time, we recommend that you change the storage class to IA rather than Archive.

• Data retrieval fees

  Data retrieval fees are incurred when you access IA objects and Archive objects. These fees are calculated separately from the outbound traffic. If you need to access an object more than once a month, we recommend that you do not set its storage class to IA or Archive.