Backup Methods — Which is Best for You?
The need to back up your organization’s data cannot be overemphasized. Dozens of internal and external risks are lurking that could send your systems offline in minutes, render company data permanently unavailable and, in the worst case, drive you out of business. From ransomware and accidental deletion, to power surges and natural disasters.
Catastrophic data loss can drive you out of business
There are different backup methods, and you have to decide which is most suitable for your business. There isn’t any one that’s best for all organizations. Your choice of backup method depends on how well it is aligned with your budget, available storage, location of storage (on premises versus cloud), volume of data, recovery point objective and recovery time objective.
The major backup methods are full, differential, incremental and synthetic full backup.
Full backups are what most people will first think of when they hear the term backup. They are a complete copy of your data. Irrespective of the backup method you eventually settle on for each system, all systems should have at least one full backup. A full backup forms a baseline for the next two backup methods covered here i.e., differential and incremental.
Full backups are as comprehensive a backup as you can get. They also have the shortest recovery time. They are not without drawbacks though. First, the time it takes to complete each backup may be as much as 10 times longer than other methods. Second, each copy takes up a large amount of storage space which means higher costs.
Full backups are as comprehensive a backup as you can get
Third, full backups tend to store large amounts of duplicate information which only exacerbates backup space, time, and cost. This duplication is not just with respect to the large quantities of unchanged data found in each subsequent full backup. There is also the duplicate information that occurs in different sections of the system or organization. For the latter, you can use deduplication to reduce the size of full backups by identifying and disregarding duplicate data.
Differential backups store files or folders changed or created since your last full backup. With each subsequent run, a differential backup copies all information that has changed since the full backup.
They take a much shorter time to do than a full backup and don’t require a lot of storage space for each backup. However, data restoration takes longer as it entails first recovering the full backup then applying the most recent differential backup to it.
Incremental backups include just the data that has changed since your last incremental backup. This sounds similar to a differential backup, but it is not the same. Here’s why.
An incremental and differential backup are the same the first time they are run immediately after the most recent full backup. However, unlike a differential backup that each time copies everything changed since the last full backup, incremental backup copies only what has been changed since the last incremental backup. In other words, the differential backup copies more information than an incremental backup but less than a full backup.
Differential backup copies everything changed since the last full backup. Incremental backup copies only what has changed since the last incremental backup
Incremental backups use the timestamp on folders and files to compare these with the time of the last backup. Of all backup methods, incremental backups take up the least amount of space. They are also faster than both differential and full backups. On the other hand, data restoration takes the longest as it means first recovering the full backup then applying all subsequent incremental backups that occurred since then.
Synthetic Full Backup
Synthetic full backups apply incremental backup changes to the last full backup effectively creating a new full backup each time. In this respect, synthetic full backups offer the best of full and incremental worlds by ensuring you always have a current full backup you can restore rapidly.
All mission-critical systems have to be backed up every day. You do not need such a high backup frequency for lower priority systems and data. In high risk industries such as financial services and information technology where just an hour of downtime can have disastrous effects, backups are done continuously through replication to a secondary site.
This makes recovery near instant. However, if the data in the primary site is corrupted, so will that in the replication site thus hampering recovery. With an array of options at your disposal, it can be difficult to know just which backup method and strategy to go for.
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