Continuous Data Protection

The traditional means of backing up a server have always been challenged by long processing times and performance issues. Incremental and full backups must read all files and folders to determine which files have changed. In the world of 24 hours web-based businesses this is not acceptable and there must be a solution. Continuous Data Protection (CDP) makes high-performance backups which save storage and are less likely to slow down the server while backups take place.

What is CDP?

CDP captures every version of data saved, allowing easier recovery and the option of going back to every point in time. Files and folders can be restored from any time interval without impacting on the server or disk operation. Every time an alteration happens, it is copied onto another disk and time between data replications doesn’t exist. CDP can be done much more frequently than other backup methods and solves many problems associated with incremental and full backups.

How does CDP work?

CDP runs a full backup only once as long as the storage medium exists. This backup is known as the initial replica and creates a record in time of the data. CDP constantly monitors any change of data and saves only changes. The user may choose an interval of every 30 minutes and the system will comply with this request. CDP works at the block level of hard disk sectors (asynchronous replication). This means that a few bytes changed within a 200-gigabyte file only results in a small sector being read from disk during the backup. Changes and timing are tracked on the server so when it is time for a backup the hard disk will be used sparingly.

Other Features of CDP

  • It reduces storage needs by only saving changes to data after the first virtual full backup. CDP also recycles old data
  • It provides a snapshot of the server at numerous increments such as every hour in a 24 hour period or every day in the last week
  • It only keeps a minimum of data for the disk sectors points in time.
  • It allows improved recovery point of objectives by allowing short intervals amid backups
  • It can restore an entire server to a previous state without re-installation of an Operating System.

Why did CDP Come About?

  • Hard drives are becoming bigger and more data is generated. The speed of hard drives have not changed too much so it takes longer to backup data
  • CDP was a reaction against some of poor performing incremental backups. It may take hours or days to do the backup so frequent backups are out of the question. Reading the data takes a long time and affects the performance of the hard drive during an incremental backup.

Advantages of CDP

  • It has a record of all transactions that have taken place within a company
  • System infections like viruses and corrupted files can be discovered later and recent clean copies of the problem file can be found easily.
  • Data recovery can happen in seconds rather than hours unlike tape or archived backups
  • The installation of the hardware and programming is easy and doesn’t risk data

Disadvantages of CDP :

  • The local disk is only updated after replicated data has been written to the target disk and the acknowledgment has been sent to the production server.
  • Performance of the production application is slow while the user learns if the replication has occurred.
  • It requires special hardware which can be costly and complex for some companies

The benefits of CDP are profound and have the potential to lessen the need for other forms of backup. The efficiency, overall performance of the backups, monitoring capabilities and recovery points out performs most other types of backup. CDP is part of the evolution of backup technology and will continue to define the backup industry in the future.