Few days ago i talked about “Point-in-time recovery : Backup solution for enterprise and business” in which we talked about point in time concept. That particular concept is nearly perfect but it does have a drawback if the enterprise need to recover data that got lost between the two scheduled backups.
For some enterprises and businesses , losing even a small amount of data is not acceptable because of the critical nature of the data and loss caused by losing even the small data either in terms of money or reputation of the enterprise or business , hence data loss by any means simply isn’t an option.
So whats the solution. A Online Backup concept which comes in handy for something like this is widely known as Continous data Protection or CDP in short.. In this article i will talk about in layman terms as much as i can do. As per definition of CDP on wikipedia :
Continuous data protection (CDP), also called continuous backup or real-time backup, refers to backup of computer data by automatically saving a copy of every change made to that data, essentially capturing every version of the data that the user saves. It allows the user or administrator to restore data to any point in time.
So what makes it different from scheduled backups or normal backup or point in time backups? If you read the definition above you will know. Continuous data protection (CDP) technology saves every write/delete operation on harddisk on a file in real time. Its like a real time synchronisation of the actual data and the backup.
Conventional backup methods depend on the scheduled backups to restore data. That means you cannot restore data between the two backups. While with CDP you can specify the exact point of time at which you want your data to be restored.
With Continuous data protection (CDP), in the event of system being infected either due to virus/Trojan, or if data gets damaged/lost or corrupted and the problem remains undetected for some time for whatever reasons, it is always possible to recover the most recent clean copy of affected data from the online backup CDP copy.
One of the bottlenecks connected with this technology is full availability of network bandwidth. Any disruption in traffic or network disruption can seriously impair CDP operation. Some companies providing this technology avoid this by resynchronizing the data once the network disruption passes, but data corruption is a serious possibility in that amount of time of disruption.
Many experts point out that CDP concept of backup needs anywhere from 5% to 40% additional storage overhead, which i dont think is too much extra storage space required compared to benifits of the technology.
With these advantages, CDP is used to continuously back up crucial corporate data on file servers and transiently connected machines to minimize the backup/recovery window and maximize the granularity of recoverable data.
I wrote this article in simple terms avoiding technical terms. If you need any clarifications, just leave a comment below and i would be glad to answer you.