2 posts • joined 29 Jun 2011
Savings in network bandwidth is achieved by source-side backup solutions (such as Arkeia or Avamar). Only unique blocks not previously saved are sent to the backup server, hence the bandwidth usage reduction.
My 2 cents ;)
Let me see if I can help to understand this :)
I agree with you that you should always retain at least 2 copies of backups in different locations. But there is no interest to keep redundant data on the same backup storage (whatever it is disk or tape).
For example, if you backup the user folder of 20 sales people using the same ppt presentation with only the first slide modified (sales person name + company presented it to) you might have hundreds occurrences of the "almost" same file: block-level dedupe allows you to dedupe within all these files, across all the backed up machines (for the products able to dedupe across all backed up machines).