Use a snapshot to create a new cloud disk for data replication - Elastic Compute Service

You can create a new data disk from a snapshot. The new disk is an exact replica of the source data disk at the time the snapshot was taken. You can replicate cloud disk data within the same or different availability zones for environment cloning or data backup. This topic describes how to create a new data disk from a snapshot.

Limitations

You cannot create snapshots for local disks or elastic ephemeral disks. Therefore, you cannot use their snapshots to create data disks.
Block storage devices are independent and cannot be merged after creation. You cannot combine the storage space of multiple block storage devices by formatting them. We recommend that you plan the number and capacity of your block storage devices in advance.
A cloud disk created from a system disk snapshot can be used only as a data disk. If you want to restore data to the original system disk from a snapshot, see Roll back a cloud disk by using a snapshot.

Prerequisites

You have created a snapshot for a cloud disk and obtained the snapshot ID. For more information, see Create a snapshot for a disk.
If you plan to attach the cloud disk to an ECS instance during creation, obtain the instance ID beforehand.

Procedure

Note

You can perform this operation from multiple entry points: the cloud disk purchase page (in the Cloud Disk section, select Create from Snapshot), the instance purchase page (in the Data Disk section, select Create from Snapshot), or the Snapshots page. This procedure uses the Snapshots page as an example.

Go to ECS console - Snapshots.
In the upper-left corner of the page, select a region and resource group.
Find the snapshot from which you want to create a cloud disk. In the Operation column, choose > Create Disk.

On the cloud disk purchase page, configure the parameters.

Parameter	Description
Attach	Whether to attach the cloud disk to an instance after creation. Not Attach: Creates a pay-as-you-go cloud disk without attaching it to an instance. Except for zone-redundant ESSDs, a cloud disk must be in the same zone as the ECS instance. Select the Region and Zone carefully. Attach to ECS Instance: Creates and attaches a cloud disk to a specified ECS instance in the same zone. Zone-redundant ESSDs can be attached to instances in any supported zone within the same region. See Limitations. You must select the target region and ECS instance.
Billing Method	The billing method of the cloud disk. Pay-as-you-go: Attachable to subscription or pay-as-you-go instances. Subscription: Must be attached to a subscription instance.
Cloud Disk	The snapshot information is automatically populated. Select the new cloud disk type and capacity. The capacity of the new cloud disk must be greater than or equal to the capacity of the snapshot's source disk. Important If the new cloud disk is larger than the source disk, you must extend its partition and file system to use the additional capacity. If the snapshot's source disk is smaller than 2,048 GiB but you want to set the new disk capacity to be greater than 2,048 GiB, first confirm that the source disk uses the GUID Partition Table (GPT) format. To do this, run the `fdisk -lu` command and check if the value of `Disk label type` is `gpt`. Otherwise, we recommend that you set the capacity to less than 2,048 GiB to avoid the risk of data loss when you configure partitions. For more information, see Initialize a data disk on a Linux instance. Performance: Available only for ESSDs. The performance level depends on ESSD capacity. See ESSDs. Multi-attach: Attaches a single ESSD to multiple instances in the same zone. See Enable the multi-attach feature. Encrypt: Automatically encrypts data on the cloud disk. See Encryption. Provisioned Performance Fee and Enable Burst: Required for ESSD AutoPL disks. Configure provisioned performance and burst settings. See ESSD AutoPL. Release settings: If you select Attach to ECS Instance with Pay-as-you-go billing, you can specify whether the disk and its automatic snapshots are released with the instance.

Confirm the configuration and fee, and then complete the purchase as prompted.

After the disk is created, you can view it on the Cloud Disks page. However, you cannot immediately use the disk on an ECS instance.

What to do next:

Important

A cloud disk created from a snapshot already contains partitions and a file system, so you do not need to initialize it. You only need to attach it to an ECS instance and then mount the file system in the operating system to make the disk usable.

Scenario	Next step
You selected Attach to ECS Instance when you created the cloud disk.	Mount the disk or bring it Online. Linux instance Connect to the ECS instance to which the cloud disk is attached, and run the following command to complete the `mount` operation. `sudo mount <disk partition name> <mount point>` `<disk partition name>`: Obtain this by running the `sudo fdisk -lu` command. For example, `/dev/vdc`. `<mount point>`: The mount point can be an existing directory, or you can create a new directory by running the `sudo mkdir -p <new directory>` command. For example, `sudo mkdir -p /data`. Example `mount` command: `sudo mount /dev/vdc /data` Add the new partition information to the `/etc/fstab` file to automatically mount the partition at startup. For more information, see Automatically mount a data disk on a Linux instance. Windows instance Connect to the ECS instance to which the cloud disk is attached. Open Server Manager, and then choose Disk Management. Find the target disk, right-click the disk's blank area, and select Online. (Conditionally required) On a Linux instance, if you attach the new cloud disk to the same ECS instance as the source disk, a UUID conflict will occur. You must change the UUID of the new cloud disk. For more information, see Change the UUID of a disk partition. (Conditionally required) If the capacity of the cloud disk created from a snapshot is larger than the capacity of the source disk, you must extend the partitions and file systems before you can use the disk's full capacity. For Linux instances, see Extend partitions and file systems of a disk on a Linux instance. For Windows instances, see Extend partitions and file systems of a disk on a Windows instance. (Optional) Configure the cloud disk partition to automatically mount at startup. For more information, see Automatically mount a data disk on a Linux instance.
You selected Not Attach when you created the cloud disk.	You need to attach the cloud disk to an ECS instance and mount its file system in the operating system. For more information, see Attach a data disk.

FAQ

How do I use a cloud disk created from a snapshot to recover data if an ECS instance becomes unavailable due to an attack or intrusion?

Note

If you created a system disk snapshot before the attack occurred, you can use it to roll back the system disk to the state it was in when the snapshot was created. For more information, see Roll back a cloud disk by using a snapshot.
Snapshots created after an attack may contain malicious code or tampered data. The following procedure is for reference only. Adapt these steps to your specific deployment.

Create a snapshot of the system disk to back up your data. For more information, see Create a snapshot for a disk.
Re-initialize the system disk to clear its data. For more information, see Re-initialize a disk.
Follow the procedure in this topic to create a temporary pay-as-you-go cloud disk from the created snapshot.
Attach the newly created temporary disk to the original instance as a data disk. For more information, see Attach a data disk.
Copy the business data from the temporary disk to the original system disk and manually redeploy your services, including applications and configurations.
Detach and release the temporary cloud disk. For more information, see Detach a data disk and Release a disk.