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    Simple Application Server:Manage snapshots

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    Simple Application Server:Manage snapshots

    Last Updated:Oct 15, 2024

    A snapshot is a point-in-time backup of a disk. Snapshots can be used to back up data, recover data after accidental operations on servers, recover data after network attacks, and create custom images. This topic describes how to create and delete snapshots, roll back disks based on snapshots, and create custom images based on snapshots in the Simple Application Server console.

    Usage notes

    Note

    You are not charged for creating snapshots for disks of simple application servers.

    • You can create up to three snapshots for each simple application server.

    • The maximum number of snapshots that can be retained in an Alibaba Cloud account is triple of the number of simple application servers that you have. The value cannot be greater than 15.

    • If a simple application server is automatically released due to expiration, the snapshots created for the server are deleted.

    • If you reset a simple application server, the snapshots that are created before the server is reset are retained, but the snapshots cannot be used to roll back the disks of the server.

    Billing

    You are not charged when you create snapshots.

    Create a snapshot

    1. Log on to the Simple Application Server console.

    2. In the left-side navigation pane, click Servers.

    3. Find the server for which you want to create a snapshot and click the server ID in the server card.

    4. Click the Disk tab.

    5. Find the system disk or data disk for which you want to create a snapshot and click Create Snapshot in the Actions column.

      If no data disk is mounted to your simple application server, you can create snapshots only for the system disk.

    6. In the Create Snapshot dialog box, confirm the disk information, enter a snapshot name, and then click OK.

      To ensure that the snapshot is created, we recommend that you do not stop or restart the simple application server. It takes about 10 to 30 minutes to create a snapshot.

    7. Click the Snapshots page to view the snapshot information.

    Roll back a disk based on a snapshot

    Important

    After you reset a simple application server, you cannot roll back the disks of the server based on a snapshot that is created before you reset the server.

    Before you roll back a disk of your simple application server, take note of the following items:

    • The rollback operation is irreversible. After a disk is rolled back, all data changes that you made from when the snapshot was created to when the disk is rolled back are lost. To prevent data loss caused by accidental operations, we recommend that you create a snapshot for a disk to back up the disk before you roll back the disk.

    • If the simple application server is in the Running state when you roll back the disk, the system stops the server before it rolls back the disk.

    1. Log on to the Simple Application Server console.

    2. In the left-side navigation pane, click Servers.

    3. Find the server for which you want to roll back a disk based on a snapshot, and click the server ID in the server card.

    4. Click the Snapshot tab.

    5. Find the snapshot that you want to use for the rollback operation and click Rollback in the Actions column.

    6. In the Rollback Disk dialog box, confirm the disk information and click OK.

      The system stops the simple application server to roll back the disk and then restarts the server for the rollback operation to be complete.

    Delete a snapshot

    Warning

    If you delete a snapshot, you cannot restore the backup file of the data on the disk for a specific point in time. Make sure that you no longer need the snapshot before you delete it.

    1. Log on to the Simple Application Server console.

    2. In the left-side navigation pane, click Servers.

    3. Find the server whose snapshot you want to delete and click the server ID in the server card.

    4. Click the Snapshot tab.

    5. Find the snapshot that you want to delete and click Delete in the Actions column.

    FAQ

    Q1: Does a simple application server support automatic snapshot policies?

    A1: No. A simple application server does not support automatic snapshot policies. You must manually create snapshots. You can retain up to three snapshots for a single simple application server. The maximum number of snapshots that can be retained in an Alibaba Cloud account is three times the number of simple application servers created in the account and cannot exceed 15.

    Q2: What do I do if I cannot use snapshots to roll back a simple application server after I reset the simple application server?

    A2: A snapshot created before you reset a simple application server or replace the image of the server cannot be used to roll back the server after you reset the server or replace the image of the server. However, you can use the following solution:

    1. Create a custom image based on the snapshot that was created before you reset the simple application server. For more information, see Create a custom image.

    2. Reset the simple application server by using the custom image that you created. For more information, see Reset a simple application server.

      Warning

      To prevent data loss after the simple application server is reset, we recommend that you create a snapshot to back up data before you reset the server. For more information, see the Create a snapshot section of this topic.

    Related operations

    You can create custom images based on snapshots to save the data of simple application servers. The custom images can be shared to Elastic Compute Service (ECS) or used to create simple application servers that have the same configurations. For more information about custom images, see Overview of custom images.