Synology Cloud Station (SPR)

Synology Point Recovery (SPR)

Synology Cloud Station the (SPR (Synology Point Recovery) is a technology that achieves data synchronization by aligning versions across all connected clients. In an SPR, modification of a particular file is a recovery point in time which is roughly translated to a snapshot of the volume. A recovery point consists of "patches" which determine the difference from the previous recovery point. The Cloud Station server keeps its clients in sync by continuously synchronizing the restore points of each file, advancing or returning them to match the synchronization status to the database version. There are many benefits to SPR technology. Instead of storing each version of the entire file, Cloud Station maintains a historical version gradually, with each version 9 associated with the previous patch. 

The patch also contributes to a very efficient and economical way to save from database maintenance for version retrieval / recovery. That is also to say, only modified bytes are found between each version that needs to be sent after the update. This reduces network traffic that is needed significantly. The SPR operates with the help of monitoring and changing Cloud Station file system notifications on the server and client side. The following sections describe monitoring and voting mechanisms (which form a communication channel between clients and servers related to file changes) and how the Cloud Station database version handles these changes at the time of receipt.

DiskStation failed, it might want to recover data stored on the hard drive. Data stored on DiskStation hard drives can be easily restored using live Ubuntu CDs and computers. Please see the steps below. Prepare a PC with enough hard disk slots available to install the hard drive from DiskStation. Remove the hard drive from DiskStation and connect it to your computer. For RAID or SHR configurations, you must connect all hard drives (not including hard drives used as hot spares) to the computer at the same time. Note: Make sure the file system running on your Synology NAS hard drive is EXT4 or Btrfs.

Monitoring Mechanism (Notification of Local File Change)

Cloud Station uses the native API to monitor file system changes on servers and clients. They allow the Cloud Station software to be immediately notified of file changes to begin the synchronization process. The APIs used on various platforms are listed below:, Windows: ReadDirectoryChangesW, Mac OSX: XNU Linux and Android Fault: inotify iOS: N / A (iOS application running in sandbox) Synology NAS: continued inotify. The Cloud Station client utility functions by playing between polls and event withdrawals. 

By polling, each client gets the latest synchronization status from the server and continues to pull changes to the "pull event", allowing for efficient and updated low latency data on the client side. The Cloud Station and Cloud Station Client polling mechanism uses the traditional Linux inotify API to monitor changes to the file system on the Synology NAS. To improve the efficiency of monitoring the file system, Synology implements several changes to the traditional inotify API on the Linux kernel from Synology NAS (available on Linux 3.x kernels), which is able to simultaneously monitor more files and folders.