Dedupe makes a big difference

A breakthrough in virtual tape technology came when dedupe technology was integrated with VTLs. Like previous-generation VTLs, dedupe VTLs require backup software products to generate backup data, but the dedupe function eliminates redundant data from backup streams. This translates directly into backup storage capacity savings and makes them much more cost-competitive with tape systems. Not only that, but dedupe VTLs improve backup  performance by simultaneously backing up a larger number of servers and by keeping more backup copies readily available online. Many organizations
happily replaced their tape backup systems with dedupe VTLs.

While dedupe VTLs have transformed backup for many IT teams, it has done relatively little to make disaster recovery easier. In most cases, tape copies still need to be made for off-site protection and the challenges of restoring data from tape are the same whether they were generated by tape drives or a dedupe VTL. However, like incremental-only backup solutions, some dedupe VTLs can also replicate data off site to another remote dedupe VTL, eliminating the need to make off-site tape copies—with the familiar caveats that remote replication adds additional systems and facilities costs as well as being more complicated to manage.


Dedupe variations: source and primary dedupe
Due to the success of dedupe backup systems, most people associate dedupe technology with target-side backup protection, but the technology can be successfully implemented other ways as well. Source dedupe implements dedupe technology before sending it over the network to be backed up. The main advantage of source dedupe is that it consumes far less bandwidth to transfer data and the main disadvantage is that it takes more processing resources on the server where the dedupe process runs.

Primary dedupe is the application of dedupe technology for primary production data, as opposed to being limited to backup data. The main advantage of primary dedupe is that it reduces the amount of capacity consumed on primary storage— which tends to be the most expensive storage in the data center. The main disadvantage of primary dedupe is the performance impact of running dedupe on production data.

Source of Information : Rethinking Enterprise Storage