Restoring an Object from Cold Storage

• After versioning is enabled, if you do not specify a version ID, OBS restores the current version. You can specify a version ID to restore a specific version.
• If the RestoreObject API is called for the first time, the server returns 202, indicating that the server has received the request. If the RestoreObject API is called again after a successful object restore, 200 OK will be returned.

• If a Cold object is being restored, its restore task cannot be suspended or deleted.
• An object being restored cannot be restored again.
• After an object is restored, an object copy in the Standard storage class will be generated. This way, there is a Cold object and also its Standard copy in the bucket. The copy will be automatically deleted once the restoration expires.

OBS provides two restore options: standard and expedited.

To restore a large number of objects from the Deep Archive storage class, you are advised to use the standard restore. The restore time spent depends on the object size restored.

Object Restore Process

The following gives an object restore example:

1. Before a restore, an object is in the unrestored state.
2. On July 1, you submit the first restore request. The object enters the restoring state.
3. On July 1, the server completes the restore operation. The object enters the restored state and becomes readable. Assume that you set the validity period to 10 days this time. The object will remain restored until July 10.
4. On July 5, you make another restore request for the object and set the validity period to 10 days. The object will then remain in the restored state until July 15, with a total validity period of 15 days.
5. Once the validity period is reached, the object returns to the unrestored state and is stored in its original storage class.

Cumulative Validity Period Rule

If you initiate a restore request for an object at time A and set the validity period to N days, the restore expiration time will be A + N. Later, you make another restore request for the object at time B (B is earlier than A + N) and set the validity period to M days:

• If B + M is later than A + N, the expiration time changes to B + M, and the total validity period is (B – A) + M, as shown in Figure 1.

  Figure 1 Cumulative validity periods

  
  
• If B + M is earlier than A + N, the second restore will fail.

You have the obs:object:RestoreObject permission.

You can use OBS Console, APIs, SDKs, or obsutil to restore Cold or Deep Archive objects.

1. In the bucket list of OBS Console, click the required bucket to go to the Objects page.
2. Select the file you want to restore, and click Restore on the right. The following dialog box shown in Figure 2 is displayed.

   You can select multiple files and click Restore above the file list to batch restore the files.

   You can select multiple files and choose More > Restore above the file list to batch restore them.

   Note

   Objects that are being restored cannot be added for batch restore.

   Figure 2 Restoring an object

   
   

3. Configure the validity period and speed of the restore. The following table describes the parameters.

   Table 2 Parameters for restoring objects

   Parameter	Description
   Validity Period	How long the object will remain in the Restored state. It starts once the object is restored. The value is an integer ranging from 1 to 30 (days). The default value is 30. For example, if you set Validity Period to 20 when restoring an object, 20 days after the object is successfully restored, its status will change from Restored to Unrestored.
   Speed	How fast objects will be restored. Expedited: Cold objects can be restored within 1 to 5 minutes. Standard: Cold objects can be restored within 3 to 5 hours. Bulk: Large amounts, even gigabytes, of data can be restored within 5 to 12 hours at a low cost.

4. Click OK.
   Note

   The system checks the file restore status at UTC 00:00 every day. The system starts counting down the expiration time from the time when the latest check is complete.

For details, see "Restoring Cold Objects" in the API Reference Guide.

See section "Restoring Objects from the Cold Storage" in the Object Storage Service Tools Guide (obsutil).

Within the validity period of a restored object, you can restore the object again. The validity period is then extended because it will start again when the latest restore is complete.