Concepts

• CDP task: You can create a CDP task to continuously back up your VM data to a specified backup server to achieve continuous data protection and recovery.
• Recovery task: A recovery task helps you quickly restore data by specifying a CDP task and recovery point, and allows you to view the recovery progress and logs in a more friendly way.
• CDP data: The backup data generated from continuous data protection on VM instances is stored in local backup servers.
• Recovery point: A recovery point is a data point generated during continuous data protection. A recovery point corresponds to a data record within the recovery point interval specified by the user.
• Locked recovery point: You can lock or unlock a recovery point as needed. After a recovery point is locked, data of the recovery point will not be automatically cleared or deleted.

How CDP Works

ZStack Cloud provides block-level continuous data protection. You can restore CDP data according to a specified time point.

• CDP backup

  After continuous data protection is performed on a VM instance, the CDP server first performs a full copy of the VM data, continuously captures I/O data changes, and timestamps, and saves the I/O data of each change, thereby achieving continuous data backup.

  
  
  

• CDP recovery

  When data recovery is performed, the CDP server exposes the CDP data as a block device and then restores the I/O data at a specified time to the disk or file system of a primary storage.

  
  
  

Advantages

• Simple:
  • The software-defined solution we provide is hardware-independent and scalable.
  • You can preview the backup files without restoring the system. Supported file formats: pictures (.png, .jpg, .bmp, .gif, etc.), PDF files, and text files (equal to or smaller than 10 MB).
  • When you create a CDP task for the first time, the Cloud intelligently recommends the desired capacity required by a CDP task based on an algorithm, helping you to plan the backup space reasonably.
  • You can restore data through a wizard-style process.
• Strong:
  • Agentless backup: To use the CDP service, you do not need to install agents for your VM instances or couple with other applications. This helps reduce the configuration complexity, lower the VM performance loss, and guarantee the business security.
  • Second-level RPO: Provides second-level fine-grained continuous data protection for VM instances.
  • Instant recovery: Supports instant recovery with the RTO in seconds, which helps to ensure the business continuity.
  • Primary storage support: The CDP service applies to VM instances in different primary storage scenarios, including local, NFS, SharedBlock, and Ceph primary storages.
• Flexible:
  • Flexible RPO settings: Provides second/minute-level RPO settings.
  • Multiple recovery levels: Supports entire recovery and file-level recovery.
    • Entire recovery: You can restore data to the original VM instance or to a newly-created VM instance.
    • File-level recovery: You can retrieve files without restoring the system. Both Windows and Linux file system formats are supported.
  • Flexible data display and search:
    • The CDP data page displays hourly data changes of a VM instance, which provides a reference for backup capacity planning.
    • The CDP data page also provides a recovery point calendar, which identifies the dates with recovery points with colors. This helps you locate a recovery point quickly.
• Reliable:
  • Unified O&M: You can view the critical CDP information on the CDP overview page, including the CDP task status, recovery task status, backup server usage, and unread CDP alarms.
  • You can restore CDP data to the original VM instance by creating a volume for the VM instance. All of the volumes before recovery can be retained and attached to the VM instance again, which ensures the data security to the maximum extent and facilitates post-fault analysis.
  • The "Create VM instance" recovery policy allows you to create a new VM instance from the selected recovery point without affecting the original VM instance. You can finish the recovery after you confirm that the data is correct. This helps to meet the recovery drill requirements.
  • You can mark and lock recovery points to retain the recovery point data in long term.
  • The Cloud provides a list of recovery tasks, allowing you to view the recovery records and progress in a more friendly way.
  • The RPO latency policy and alarm help to effectively relieve data transmission pressure of backup servers in heavy I/O scenarios.

Scenarios

Limits

Currently, if a VM instance has volumes not stored on the Ceph primary storage, you could not clone the VM instance or create snapshots or images for the VM instance during CDP.