A high percentage of data that is retained on backup media by most backup solutions is highly redundant. The typical backup process for most organizations consists of a series of daily incremental backups and weekly full backups.
Daily backups are usually retained for a few weeks and weekly full backups are retained for several months to several years. Because of this process, multiple copies of identical or slowly changing data are retained on backup media, leading to a high level of data redundancy.
A large number of operating system, application files and data files are common across multiple systems in an enterprise. Identical files such as Word documents, PowerPoint presentations and Excel spreadsheets, are stored by many users across an environment. Backups of these systems will contain a large number of identical files.
Additionally, many users keep multiple versions of files that they are currently working on. Many of these files differ only slightly from other versions, but are seen by backup applications as new data that must be protected.
Backing up redundant data increases the amount of backup storage needed and can negatively impact network bandwidth. Organizations are running out of backup window time and facing difficulties meeting recovery objectives due to the need to manage backup versions and a myriad of backup tapes.
Avamar differs from traditional backup and restore solutions by identifying and storing only unique, sub-file data objects. Redundant data is identified at the source, drastically reducing the amount of backup data that travels across the network to be stored and managed by the backup host. When storing data objects, Avamar takes maximum advantage of inherent hard-disk characteristics. Avamar also creates and stores “trees” that link all data objects from a single backup. These “trees” are used to re-create files for restore.
