Backup is one of the most important tasks for any system administrator, as it can save your organization from data loss, downtime, and disaster. But how do you choose the best backup method for your specific needs and goals? In this article, we will explore some of the most common backup strategies and methods, and help you decide which one suits your organization best.
A full backup is the simplest and most comprehensive backup method, as it copies all the data from your source to your destination. It is also the easiest to restore, as you only need one backup set to recover your entire system. However, a full backup also has some drawbacks, such as taking longer time, consuming more storage space, and increasing the risk of data corruption or theft. Therefore, a full backup is usually recommended for critical or sensitive data, or for the initial backup of a new system.
The best backup method for organizations typically involves a combination of regular automated on-site and off-site backups, along with data rotation, encryption, testing, and a well-defined disaster recovery plan. This multi-layered approach ensures data security, availability, and resilience against various risks.
Determining the best backup method for your organization depends on various factors. Consider the size of your organization, data volume, recovery time objectives (RTOs), and budget. Options like full backups, incremental or differential backups, and cloud-based solutions are common. Choose a backup method that aligns with your specific needs. Implementing a combination of on-site and off-site backups ensures data redundancy and protection against disasters. Regularly test your backups to verify their integrity and perform periodic reviews to adjust your backup strategy as needed.
Full backups are good to get on a regular basis. I like to get them quarterly at the minimum. But for larger targets, that can be a problem, so you might have to deal with synthetic full backups to get that baseline (after the first). These can be risky - be sure to test them!
An incremental backup is a more efficient and flexible backup method, as it only copies the data that has changed since the last backup, whether it was a full or an incremental one. This way, you can save time, storage space, and bandwidth, and also reduce the impact of backup on your system performance. However, an incremental backup also has some challenges, such as requiring more backup sets to restore, depending on the backup frequency and retention policy. Therefore, an incremental backup is usually recommended for dynamic or frequently updated data, or for regular backup of an existing system.
Incremental backups depend on the entire history - every preceding incremental and the baseline full. That can really get out of hand as the numbers of incrementals grow.
A differential backup is a compromise between a full and an incremental backup, as it copies the data that has changed since the last full backup. This way, you can still save some time, storage space, and bandwidth, compared to a full backup, and also simplify the restoration process, compared to an incremental backup. However, a differential backup also has some limitations, such as growing larger and slower over time, and needing to perform a full backup periodically. Therefore, a differential backup is usually recommended for moderate or occasionally updated data, or for weekly or monthly backup of an existing system.
Differentials are rarely used in practice because they're tricky to use effectively as compared to simpler incremental/full cycles.
A mirror backup is a special type of backup method, as it creates an exact replica of your source data on your destination, without any compression or encryption. It is also the fastest and most convenient backup method, as it synchronizes your data in real time, and allows you to access your backup data directly. However, a mirror backup also has some risks, such as deleting any data that is deleted from your source, and exposing your backup data to the same threats as your source data. Therefore, a mirror backup is usually recommended for temporary or non-essential data, or for local backup of an individual system.
A cloud backup is a modern and popular backup method, as it leverages the power and scalability of cloud computing to store your data on remote servers. It is also the most secure and reliable backup method, as it protects your data from physical damage, theft, or loss, and offers multiple layers of encryption and redundancy. However, a cloud backup also has some costs, such as requiring a stable and fast internet connection, and paying for the cloud storage and services. Therefore, a cloud backup is usually recommended for remote or distributed data, or for offsite backup of an organization system.
Consider deduplication to reduce your storage load, especially for incremental backups. A decent dedupe system can reduce your stage requirements by 90%.