Disk Image vs File backups: The Pros and Cons

There are all sorts of backup set types to choose from, and at times it can become a bit unclear what choices are best for your strategy. I'd like to walk you through a comparison of images and file level backups in particular. The question of which to use when is an important one, as the choice will have a cost both in time, resources and man hours. An effective strategy is important to making the most out of a 3X Remote Backup Appliance.

Disk Image backups

Pros:

• OS and Applications backed up intact
• Entire system restore speed

Cons:

• Performance of backup set
• Storage space requirements
• Resource requirements (network and system I/O)

The primary points in favor of Disk Image backups are the fact that the OS and applications installed on the device are intact upon backup and restore, and the speed in which an entire system can be brought backup. The trade off for these benefits however is a backup set with large storage requirements, as well as possible I/O saturation (be it network or disk). It is best to use this backup set type for especially critical servers such as a domain controller, or an email server. More or less the infrastructure that your business would absolutely *need* to operate. Another use for this style of backup is with Virtual Machines that are on non Hyper-V hosts.

File backups

Pros:

• Backup performance and storage (de-duplication)
• Simplicity of set up (less administrative involvement)
• Reliability

Cons:

• Full system restore requires OS install and application install

File backup sets have the advantage of being simple to set up, as a rule set with a destination is all you need to define the target. File backup sets also take advantage of de-duplication, and is significantly cheaper in time and resources than disk imaging in most cases. File backup sets also allow for the restoration of specific files in instances where you don't need the whole system restored.

The conclusion to draw here is that you need to tailor your choices based on the type of infrastructure you are backing up. For particularly critical servers and systems using both of these is a good idea, but for most cases simply having a file backup set is ideal.