Creating an EVS Snapshot

Scenarios

You can create EVS snapshots to save disk data at specific time points. Before you perform any critical operation, such as a data rollback, software upgrade, or data migration, you are advised to create snapshots to back up data. This ensures that your data is not affected even if an exception occurred during the operation.

During the snapshot creation, disk I/Os are affected, so you may experience slow reads or writes at some points. It is recommended that you create snapshots at off-peak hours.

Prerequisites

Snapshots can only be created for Available or In-use disks.

Notes and Constraints

Snapshots can be created for both system disks and data disks.
Snapshots of encrypted disks are stored encrypted, and those of non-encrypted disks are stored non-encrypted.

Snapshot function in OBT (view supported regions)

You can manually create a maximum of seven snapshots for a disk.
The enterprise project of a snapshot is the same as that of the snapshot's source disk.

Snapshot function in commercial use (view supported regions)

You can manually create a maximum of 256 standard snapshots for a disk, of which up to seven can have Instant Snapshot Restore enabled.
You can create one standard snapshot for a disk at a time. You can only create the next standard snapshot for the same disk after the previous snapshot has been created.
Standard snapshots cannot be created for the disks in edge AZs. For details about the differences between edge AZs and general AZs, see the CloudPond User Guide.
When standard snapshots are created for Common I/O and High I/O disks, Instant Snapshot Restore cannot be enabled.
It usually takes several minutes to create a standard snapshot. The time required varies depending on the amounts of data written to the disk. The larger the data volume, the longer the time required. The initial standard snapshot usually takes more time because data of the entire disk is backed up. Subsequent standard snapshots are quicker, but the time required is still determined by the amounts of changed data compared with each last snapshot. The more the changed data, the longer the time required.
If the data on a disk is rolled back from a snapshot, the next standard snapshot created for this disk will be a full snapshot.
During the creation of a standard snapshot, any incremental data written to the disk will not be backed up to the snapshot created.
During the creation of a standard snapshot, deleting the snapshot's source disk does not affect the creation of the snapshot.

Snapshot Function in OBT

Creating a Snapshot on the Disks Page

Log in to the management console.
Click in the upper left corner and choose Storage > Elastic Volume Service.

The Elastic Volume Service page is displayed.

In the disk list, locate the target disk and click Create Snapshot in the Operation column.

Configure the snapshot parameter according to Table 1.

**Table 1** Snapshot parameter
Parameter	Description	Example Value
Snapshot Name	Mandatory The name can contain a maximum of 64 characters.	snapshot-01

Figure 1 Create Snapshot

Click Create Now.
Go back to the Snapshots page to view the snapshot creation information.

After the snapshot status changes to Available, the snapshot has been created.

Creating a Snapshot on the Snapshots Page

Log in to the management console.
Click in the upper left corner and choose Storage > Elastic Volume Service.

The Elastic Volume Service page is displayed.

In the navigation pane on the left, choose Elastic Volume Service > Snapshots.

On the Snapshots page, click Create Snapshot.

Configure the snapshot parameters according to Table 2.

**Table 2** Snapshot parameters
Parameter	Description	Example Value
Region	Mandatory After you select a region, disks in the selected region will be displayed for you to choose from.	-
Snapshot Name	Mandatory The name can contain a maximum of 64 characters.	snapshot-01
Select Disk	Mandatory Select a disk based on which the snapshot will be created.	volume-01

Figure 2 Create Snapshot

Click Create Now.
Go back to the Snapshots page to view the snapshot creation information.

After the snapshot status changes to Available, the snapshot has been created.

Snapshot Function in Commercial Use

Creating a Snapshot on the Disks Page

Log in to the management console.
Click in the upper left corner and choose Storage > Elastic Volume Service.

The Elastic Volume Service page is displayed.

In the disk list, locate the target disk and click Create Snapshot in the Operation column.

Configure the snapshot parameters according to Table 3.

**Table 3** Snapshot parameters
Parameter	Description	Example Value
Region	The region to which the snapshot belongs. The snapshot must be in the same region as its source disk.	CN North-Beijing4
Disk Name/ID	The name and ID of the source disk.	-
Snapshot Name	Mandatory The name can contain a maximum of 64 characters.	snapshot-01Created_from_evstest
Snapshot Description	Optional The description can contain up to 255 characters.	-
Snapshot Type	The type of the snapshot. Only standard snapshot is supported currently. The time required for creating a standard snapshot depends on the size of data being backed up, but the initial snapshot usually takes a bit longer.	Standard snapshot
Instant Snapshot Restore	Snapshots with Instant Snapshot Restore enabled allow you to create disks or roll back disk data even if the snapshots are being created, and the restoration speed and creation speed are fast. For more information, see Enabling or Disabling Instant Snapshot Restore (for Snapshots in Commercial Use).	-
Advanced Settings	Optional You can add tags when creating standard snapshots. Tags can help you to identify, classify, and search for your snapshots. NOTE: You can add a maximum of 20 tags to a snapshot. Tag keys of the same snapshot must be unique. A tag consists of a tag key and a tag value. A tag key cannot start or end with a space, or start with _sys_. It can contain a maximum of 128 characters and contain letters, digits, spaces, and the following special characters: _.:=+-@ A tag value can contain a maximum of 255 characters and contain letters, digits, spaces, and the following special characters: _.:/=+-@	-
Enterprise Project	Mandatory When creating a snapshot, you can add the snapshot to an existing enterprise project or a new one. An enterprise project facilitates project-level management and grouping of cloud resources and users. The default project is default.	default

Figure 3 Create Snapshot

Click Create Now.
Go back to the Snapshots page to view the snapshot creation information.

After the snapshot status changes to Available, the snapshot has been created.

Creating a Snapshot on the Snapshots Page

Log in to the management console.
Click in the upper left corner and choose Storage > Elastic Volume Service.

The Elastic Volume Service page is displayed.

In the navigation pane on the left, choose Elastic Volume Service > Snapshots.

On the Snapshots page, click Create Snapshot.

Configure the snapshot parameters according to Table 4.

**Table 4** Snapshot parameters
Parameter	Description	Example Value
Region	Mandatory After you select a region, disks in the selected region will be displayed for you to choose from.	-
Select Disk	Mandatory Select a disk for which you want to create a snapshot.	-
Snapshot Name	Mandatory The name can contain a maximum of 64 characters.	snapshot-01Created_from_evstest
Snapshot Description	Optional The description can contain up to 255 characters.	-
Snapshot Type	The type of the snapshot. Only standard snapshot is supported currently.	Standard snapshot
Instant Snapshot Restore	Snapshots with Instant Snapshot Restore enabled allow you to create disks or roll back disk data even if the snapshots are being created, and the restoration speed and creation speed are fast. For more information, see Enabling or Disabling Instant Snapshot Restore (for Snapshots in Commercial Use).	Enable
Advanced Settings > Tag	Optional You can add tags when creating standard snapshots. Tags can help you to identify, classify, and search for your snapshots. NOTE: You can add a maximum of 20 tags to a snapshot. Tag keys of the same snapshot must be unique. A tag consists of a tag key and a tag value. A tag key cannot start or end with a space, or start with _sys_. It can contain a maximum of 128 characters and contain letters, digits, spaces, and the following special characters: _.:=+-@ A tag value can contain a maximum of 255 characters and contain letters, digits, spaces, and the following special characters: _.:/=+-@	-
Enterprise Project	Mandatory When creating a snapshot, you can add the snapshot to an existing enterprise project or a new one. An enterprise project facilitates project-level management and grouping of cloud resources and users. The default project is default.	default
Select Disk	Mandatory Select a disk based on which the snapshot will be created.	volume-01

Figure 4 Create Snapshot

Click Create Now.
Go back to the Snapshots page to view the snapshot creation information.

After the snapshot status changes to Available, the snapshot has been created.