Real-time or near-real-time snapshots, replication and continuous data protection (CDP) have become common methods of protecting data in the datacentre.
But traditional backup , where copies of data or changes to data are made at regular intervals, is still very much a mainstream approach to data protection.
Here we run through the main backup types available – full, differential, incremental, and hybrids created from these such as synthetic and incremental-forever – and where appropriate discuss their pros and cons.
Full backup
This is the most fundamental type of backup available, and is where a copy is made of all data in a specified dataset. Clearly, it is also the most time consuming to create and takes up the most storage capacity. On the plus side, it can be easier to restore data from a full backup than from some other types that must be recreated from sets of changed data.
Incremental backup
With a full backup already completed, once a week, for example, incremental backups copy only data changed since the last (full or incremental) backup. The advantage is that this is the least time and storage space-consuming method of backup. The fly in the ointment is that to restore data you must reconstruct it from the last full backup plus all intervening incrementals.
