Overview
Real-time replica of online data
A snapshot is a fully functional copy of a cloud disk. In the event of an issue with a cloud disk for which a snapshot has been created, the snapshot can be used to swiftly restore the disk to its pre-issue state. It is recommended to create a snapshot of the relevant cloud disk prior to significant business changes, allowing for rapid data recovery in case of a failed business change.
Persistent backup for key milestones
Snapshots can serve as a long-lasting backup for business data, preserving milestone states of the data.
Rapid business deployment
You can use snapshot files of your business to quickly clone multiple cloud disks, achieving the goal of rapid server deployment.
Scenarios
Snapshots provide a convenient and efficient data protection service, which can be used in the following business scenarios:
Daily data backup
You can use snapshots to regularly back up important business data to avoid data loss caused by incorrect operations, attacks, and viruses.
Quick data recovery
Before performing significant operations such as changing the operating system, upgrading application software, or migrating business data, you can create one or more snapshots. If any issues arise during the change process, you can promptly restore business data using the created snapshots.
Application of multiple replicas of production data
You can create snapshots of production data to provide near-real-time, authentic production data for applications such as data mining, report querying, and development testing.
Rapid environment deployment
You can create a snapshot for a cloud server and use this system snapshot to create a custom image. You can create one or multiple instances from the created image, allowing for the rapid and bulk deployment of cloud servers with the same environment, saving time on repeated configurations.
Billing
For detailed information about snapshot billing, see Snapshot Billing Overview and Snapshot Pricing Summary.
Quota Limits
Snapshot Types
Manual Snapshot
Manually create a snapshot of the cloud disk data at a specific point in time. This snapshot can be used to quickly create more cloud disks with the same data, or to restore the cloud disk to the state at that point in time in the future. For specific operations, please refer to Creating Snapshots.
Scheduled snapshots
When your business is continuously updated, you can use scheduled snapshots to provide ongoing backup functionality. Simply create a backup policy and associate it with a cloud disk to achieve continuous data backup within a certain period, significantly improving data security. For detailed operations, please refer to Scheduled Snapshots.
Note
During the snapshot creation process, there may be a situation where some application data is stored in memory and not yet persisted. This phenomenon can result in the snapshot not capturing the most recent and complete cloud disk data. Please refer to Precautions to ensure snapshot data consistency.
Case Review
Case One: Data loss due to failure to manually create a snapshot before executing high-risk operations.
For instance, Customer A has never created a snapshot for their cloud disk. One day in May 2019, due to an fio test conducted by an operator, the file system was damaged and the data could not be retrieved.
Analysis: If Customer A had created a snapshot for the cloud disk before conducting the test, they could have quickly enabled snapshot rollback after the data was damaged, promptly restoring the business.
Case 2: Failing to create scheduled snapshots for important data disk, causing data loss
For instance, Customer B had created snapshots for multiple cloud disks, but after January 2019, they did not create snapshots for newly purchased cloud disks due to cost considerations. One day in June 2019, data on a cloud disk that was not protected by a snapshot was accidentally deleted at the file system level, resulting in irretrievable data loss.
Analysis: If Customer B had configured regular snapshot protection for this cloud disk, they could have restored the data to the state at the time of the last snapshot after the data was accidentally deleted, thus minimizing the loss. After the incident, Customer B proactively created a snapshot for this cloud disk, significantly enhancing data protection.
Case 3: Rolling back with scheduled snapshot to restore business after a misopeartion
For instance, Customer C has configured snapshot protection for all cloud disks. On a certain day in May 2019, an abnormal startup occurred due to an operational error.
Analysis: Customer C promptly used a scheduled snapshot from two days prior to restore data, preventing any damage to the business.
The above are all examples of data loss due to operational errors. By comparison, it can be observed that:
In the absence of created snapshots, data recovery can be extremely difficult when issues arise with servers or cloud disks, potentially leading to significant losses.
In the case of having created snapshots, when issues arise with the server or cloud disk, data can be mostly recovered, resulting in minimal loss.
It is recommended to regularly create snapshots for different types of businesses to enhance data security and achieve low-cost, high-disaster tolerance for your operations.
Others
If you still encounter other snapshot-related issues, we provide a collection of related questions for your reference, allowing you to quickly locate and resolve your concerns.