What Is the Difference Between Hot Backup and Cold Backup?
Creating backups is essential, and their importance increases as the business expands and grows. Companies could lose data due to unforeseen events, and backups can help them retrieve or recover the data. These could include structural damage from earthquakes, hard drive failures, accidental fires, cyber-attacks, issues caused by power surges, and many similar situations.
With backups at bay, businesses can have peace of mind in any bad situation. There are two major types of backups: hot backup and cold backup. Both types offer distinctive advantages and disadvantages. There is also a third type, known as warm backup, but it is only sometimes adopted.
Let’s learn about cold backup vs. hot backup to experience a smooth backup operation without disrupting the services.
What is a Hot Backup?
Any backup taken when the server is online, databases are running, services are running, and all necessary software to provide services to the customer is running is called a hot backup.
This method enables continuous data protection without disrupting ongoing operations, ensuring minimal downtime and maximising data availability.
The customers will still be able to use the service while the backup-creating operation is running. It is like chasing two rabbits at the same time. The aliases of hot backups are online backups and dynamic backups.
Advantages of Hot Backup:
- Minimal Downtime: Hot backups eliminate the need for system shutdowns, minimising disruptions to user experience and business operations. Business continuity is the most significant advantage of hot backups.
- Real-time Data Protection: Hot backups continuously capture data changes, ensuring the backup reflects the system’s most recent state.
- Reduced Recovery Time (RTO): In the event of a system failure, hot backups enable a quicker restoration process, as the live system already synchronises with the backup data.
Disadvantages of Hot Backup:
- Increased System Overhead: Depending on the backup size, the continuous backup process will consume substantial system resources while other services are still running. The increased system overhead can slow down the backup, the server, and the services the customers use and may impact performance.
- Complexity: Hot backup implementations can be more complex than cold backups, requiring specialised software and expertise. Incremental backups can mitigate system resource utilisation, but handling incremental backups makes the already complex process even more complex.
- Potential Data Integrity Issues: Simultaneous data access from both the live system and the backup process can increase the risk of data corruption.
What is a Cold Backup?
Cold backup is any backup for which you first need to halt all the customers’ services and the databases from which data comes and goes. Then, you start copying the data and transfer it to another storage location.
This method captures a point-in-time data snapshot, providing a complete and consistent representation at the backup time.
Such backups do not ensure business continuity, and customers will suffer. However, a cold backup, also known as a static or offline backup, offers some advantages that no other backup type can offer.
Advantages of Cold Backup:
- Simplicity: Cold backups are relatively simple to implement and require minimal technical expertise.
- Reduced System Overhead: Cold backups do not consume system resources during the backup process, minimising performance impact.
- Enhanced Data Integrity: Cold backups create a static copy of the data, reducing the risk of data corruption due to concurrent access.
- No Effect of Live Viruses: Malware, live viruses, and malicious cyber-attacks will not impact the data and the backup operation.
Disadvantages of Cold Backup:
- Required Downtime: Cold backups necessitate system shutdowns, causing user experience downtime and potential disruptions to business operations, disrupting business continuity.
- Limited Data Protection: Cold backups capture data changes only at the time of the backup, leaving subsequent changes unprotected until the next backup cycle.
- Increased Recovery Time (RTO): Restoring from a cold backup will take longer, as the live system needs to copy back all the data.
A Word on Hot and Cold Storages
You will also often hear about hot and cold storage. Cold storage data is rarely used and remains dormant most of the time. You might not need to access them for years. Such data include old projects, HR and financial records, and similar documents.
On the contrary, hot storage data is the data that you need to access frequently and is essential for strategic business operations. Hot storage is indispensable to those industries that rely on real-time data.
Cold storage costs less because there is no need for high-end components like SSDs to quickly and frequently access the data.
What is Warm Backup?
A warm backup creates a ready and operational server in case of failures. The server will have everything installed, and if the primary server fails, the warm backup server will take its place to eliminate downtime.
Choosing the Right Backup Method: A Strategic Approach
The choice between a hot and cold backup depends on various factors. Let’s see what you should consider when deciding which type to use.
- Downtime: Companies that rely on real-time data, such as vehicle tracking companies that need to provide continuous data to their customers, should go for hot backups. Going offline can cause customers to lose their assets, which the customer will see as negligence.
- Disaster Recovery: Cold backups are well-suited for archival purposes and disaster recovery scenarios where downtime is less of a concern. Users frequently employ them for infrequently changing data, such as static files or backups of entire systems.
- Security: Files can corrupt during hot backups, especially if the real-time data is coming fast and in substantial volume because the content of files can change during the backup process.
- Resource Availability: Hot backups require the server and the databases to be online while taking the backups. Such a process will require substantial system resources. If you do not have high-end resources, you should go for cold backups.
- Recovery Point Objective (RPO): Can your company tolerate minor data losses in case of a failure? Hot backups capture real-time data and provide better RPO. If your company cannot tolerate significant data losses, you should choose hot backups because they take frequent backups.
- Backup Frequency: If you are required to take backups rarely because data has not changed for more extended periods, you can choose cold backups.
Conclusion
Hot and cold backup are two principal ways to protect data against loss. These two methods have their strengths and weaknesses. Identifying the primary distinction of each technique will significantly help you find the best method to protect your critical data.
Whether you prefer to focus on continuous availability, robust security, or a combination of both, assessing your organisation’s needs and limits is crucial to ensure that your data backup plan effectively protects it from data loss and interruptions.