Manage snapshots

Usage notes

• You can manually create a maximum of 128 snapshots for each file system. A maximum of 128 snapshots can be automatically created for each file system.
• If a snapshot is being created for a file system, you cannot create another snapshot for the file system.
• If a file system expires when a snapshot is being created for the file system, the file system is released and the snapshot is deleted.
• When a snapshot is being created for a file system, the performance of the file system may be slightly compromised and the IOPS may be temporarily degraded. We recommend that you do not create snapshots during peak hours.
• A snapshot is a backup of a file system at a specific point in time. When you create a snapshot for a file system, incremental data of the file system is not synchronized to the snapshot.

Manually create a snapshot

1. Log on to the NAS console.
2. In the left-side navigation pane, choose Data Service > Snapshot.
3. On the Snapshot page, click Manually Create a Snapshot.
4. In the Manually Create Snapshot dialog box, set the parameters. The following table describes the parameters.

   Parameter	Description
   File System	Select the ID of the Extreme NAS file system for which you want to create a snapshot.
   Retention Period	Select a retention period based on your business requirements. Custom duration: Specify the period for which the snapshot is retained. Unit: days. Valid values: 1 to 65536. It is permanently retained until the number of snapshots reaches the maximum limit and is automatically deleted. The snapshot that you create is permanently retained. If the number of manually created snapshots exceeds 128, the file system deletes the earliest snapshot.

5. Click OK.

Create an automatic snapshot policy

1. Log on to the NAS console.
2. In the left-side navigation pane, choose Data Service > Snapshot.
3. Create an automatic snapshot policy.
   1. On the Snapshot page, click the Automatic Snapshot Policy tab.
   2. On the Automatic Snapshot Policy tab, click Create an Automatic Snapshot Policy.
   3. In the Create Automatic Snapshot Policy dialog box, set the following parameters.

      Parameter	Description
      Created At	The hours of the day at which snapshots are automatically created. You can select one or more hours from 00:00 to 23:00. Note When snapshots are being created for a file system, the IOPS of the file system is temporarily degraded. We recommend that you set off-peak hours to create snapshots.
      Repeat Date	The days of the week on which snapshots are automatically created. You can select one or more days from Monday to Sunday.
      Retention Period	The retention period of automatically created snapshots. The default retention period is 30 days. The following options are available: Custom duration: Specify the period for which the snapshots are retained. Unit: days. Valid values: 1 to 65536. It is permanently retained until the number of snapshots reaches the maximum limit and is automatically deleted. Automatically created snapshots are permanently retained. If the number of automatically created snapshots reaches 128, the file system deletes the earliest snapshot.

   4. Click OK.
4. Apply the automatic snapshot policy.
   1. Find the automatic snapshot policy that you want to apply and click Apply to The File System.
   2. In the File System ID section of the Apply to The File System dialog box, select the file system and click the > icon to add the file system to the Apply to The File System section.
   3. Click OK.
      After you apply an automatic snapshot policy to a file system, NAS automatically creates snapshots for the file system based on the policy.

Use a snapshot to create a file system

1. Install NAS SDK for Python.

   pip install aliyun-python-sdk-core
   pip install aliyun-python-sdk-bssopenapi
   pip install aliyun-python-sdk-nas

2. Customize the code that is provided in NAS SDK for Python and run the code to create a file system.
   The following table describes the required parameters. For more information, see CreateFileSystem.

   Note The sample code creates a pay-as-you-go file system. If you want to create a subscription file system, you must customize the sample code.

   accessKeyId and accessSecret: Specify the AccessKey ID and AccessKey secret of your Alibaba Cloud account. For more information, see How can I obtain an AccessKey pair?.

   Parameter	Description
   Region	The region to which the snapshot belongs. For example, you can specify cn-hangzhou. You can call the DescribeRegions operation to query all available regions.
   Zone	The zone in the region to which the snapshot belongs. For example, you can specify cn-hangzhou-g. You can call the DescribeZones operation to query all available zones.
   ProtocolType	The protocols that the file system supports. Extreme NAS file systems support only NFS.
   StorageType	The storage type of the file system. Valid values: standard: standard advance: advanced
   Capacity	The Extreme NAS file system must have the same storage capacity as the file system for which snapshots are created.
   SnapshotId	The ID of the snapshot.

   import json
   from aliyunsdkcore.client import AcsClient
   from aliyunsdknas.request.v20170626.CreateFileSystemRequest import CreateFileSystemRequest
   from aliyunsdknas.request.v20170626.ResetFileSystemRequest import ResetFileSystemRequest
   
   client = AcsClient('<accessKeyId>', '<accessSecret>', '<Region>')
   # Use a snapshot to create a file system.
   def create_file_system():
       request = CreateFileSystemRequest()
       request.set_StorageType("advance")
       request.set_ProtocolType("NFS")
       # Pay-as-you-go
       request.set_ChargeType("PayAsYouGo")
       # Subscription
       request.set_ChargeType("Subscription")
       # The subscription cycle. Unit: months.
       request.set_Duration(1)
       request.set_FileSystemType("extreme") 
       request.set_Capacity("100")
       request.set_SnapshotId("s-extreme-03260551blg9****")
       request.set_ZoneId("cn-shanghai-f")
       request.set_accept_format('json')
       try:
           response = client.do_action_with_exception(request)
           rsp = json.loads(response)
           print(rsp)
       except Exception as e:
           print(e)
   
   if __name__ == '__main__':
       create_file_system()

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