Overview
Real-time replica of online data
A snapshot is a fully functional copy of a file system. In the event of an issue with the file system for which a snapshot has been created, the system can be swiftly restored to its pre-issue state using the snapshot. It is recommended to create a snapshot of the relevant file system prior to significant business changes, allowing for rapid data recovery in case of a failed business transformation.
Persistent backup for key milestones
Snapshots can serve as a long-lasting backup for business data, preserving milestone states of the data.
Quick business deployment
You can use snapshot files of your business to rapidly clone multiple file systems, thereby achieving the goal of swift service deployment.
How snapshots work
A file system snapshot is a block-level clone or backup. In general, the snapshot size will be larger than the data size displayed in the file system because:
The underlying data block stores the metadata of the file system.
Deleting data modifies the blocks where data is written in, which will be backed up to snapshots.
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
You can create one or more snapshots before performing significant operations such as changing the operating system, upgrading application software, or migrating business data. 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.
Quick environment deployment
You can create one or more file systems from an existing snapshot, allowing for the rapid, bulk deployment of identical business environments, thus saving time on repeated configurations.
Billing
Quota Limits
Snapshot Types
Manual Snapshots
Manually create a snapshot of the file system data at a specific point in time. This snapshot can be used to rapidly create more file systems with the same data. For detailed operations, please refer to Creating Snapshots.
Scheduled snapshots
When your business is continuously updated, you can use scheduled snapshots to provide ongoing backup functionality. By simply formulating a backup strategy and associating it with the file system, you can achieve continuous backup of file system data within a certain cycle, significantly enhancing data security. For specific operations, please refer to Scheduled Snapshots.
Note
During the snapshot creation process, there may be instances where some application data is stored in memory and not persistently stored. This situation can result in the snapshot not capturing the most recent and complete file system data. Please refer to Considerations to ensure the consistency of snapshot data.
Case Review
Case 1: Failing to manually create snapshots before a high-risk operation, causing data loss
For instance, customer A has never created a snapshot of the file system. 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 of the file system before conducting the test, they could have swiftly activated the snapshot to create a new file system and promptly restore the business after the data was damaged.
Case 2: Failing to create scheduled snapshots for important data disk, causing data loss
For instance, Customer B had created snapshots for multiple file systems, but after January 2019, they did not create snapshots for newly purchased file systems due to cost considerations. One day in June 2019, data was lost and could not be recovered from a file system that was not protected by a snapshot due to accidental deletion of data at the file system level.
Analysis: If Customer B had implemented regular snapshot protection for this file system, the data could have been restored to the state at the time of the last snapshot after the accidental deletion, thus minimizing the loss. After the incident, Customer B proactively created a snapshot for this file system, significantly enhancing data protection.
Case 3: Rolling back with scheduled snapshot to restore business after a misoperation
For instance, customer C has snapshot protection for all file systems. One day in May 2019, an error caused a boot anomaly.
Analysis: Customer C promptly used a scheduled snapshot from two days prior to restore the data, preventing any business damage.
These cases all involve data loss due to incorrect operations, but the results are different. By comparison, we can find that:
In the absence of a created snapshot, data retrieval can be extremely challenging when issues arise with the server or file system, potentially leading to significant losses.
In the event of a server or file system issue, data can be largely recovered with minimal loss, provided that a snapshot has been created.
We recommend regularly creating snapshots for businesses based on business types, enhancing data security and achieving low-cost, high-efficiency disaster recovery.