The IO image technology of SCP enables data protection based on an RPO of 1 second, where the data backup and recovery mechanism plays an important role. After QEMU sends a request to the IO buffer through an IO image, data is transmitted to the CDP module and stored in the IO harbor. An IO activity log is generated at the same time. The Recovery Point (RP) module processes the backup data stored in a local QCOW2 file and generates RPs at the specified interval (a minimum of 1 second). The Base Point (BP) module also processes the backup data and then generates full BPs and incremental BPs. DR gateway A syncs data to DR gateway B to ensure the efficiency of DR. A bypass architecture is used together with the IO splitting technology to replicate the primary service asynchronously for quick data backup and recovery. With a combination of first-time full backup, permanent incremental backup, and the Bitmap technology that can reduce storage usage, backups can be created more efficiently. DR gateways are built into the platform, and data compression and resumable upload are supported to ensure the reliability and efficiency of data sync. The figure below shows how data backup and data replication work.

1. Bypass architecture + IO splitting: The primary service asynchronously replicates IO data to the log repository (IO harbor) of CDP through the shared IO buffer. The IO data is stored in IO activity logs. RPs are generated at the specified IO activity logging interval (a minimum of 1 second). RPs must be used together with the corresponding BPs to recover data.
2. First-time full backup + permanent incremental backup: The base backup data is written to snapshots through Redirect-on-Write (ROW) with the Bitmap technology. This enables the platform to quickly create backups and perform permanent incremental backup to reduce the storage usage of backups.
3. Data sync through DR gateways: DR gateways are built into the platform, which can be used to sync data between the production center and DR center without a proxy. In addition, the platform supports data compression and resumable upload.