Rating: +1
Dawn,
The two are totally different. So, one does not supplant the other. Your backup takes periodic (incremental) or complete (full) backups of your active data, as well as snapshots (how something looked at a precise point in time). Catalogs are built so you can restore all or part of a backup, etc. The main purpose is to be able to restore you data, plus your environment – also backups are not kept forever - they are usually rotated to provide a recovery window of perhaps 3-6months depending on the specific business requirement for the data and applications, full backups may be stored longer.
Archive data is stored for long-term preservation of the content, the data is often separated from the application, and the concept of a “restore” either full or incremental is not a typical part of the functionality provided for an archival system.
The main purpose of the archive system is to provide long-term preservation, this requires that various attributes be resident within the archival system and architecture; for example data that is destined to hang-around for at least 10 years, will have to be migrated both physically and logically to support OS, application and systems upgrades; this software assisted migration capability is something that you do not usually find in a backup system; but you should find in an archival system. Archive systems should also maintain provenance data for the archived data; again something you find in an archive system, but not in a backup system. The list goes on….
If you need to preserve data either for legal, compliance or even just in case historical access then an archive system provides a clean way to do this; the archive will not replace the backup/restore function. So you always need a backup, mostly for the restoration of the “environment”.
All of that said; an archive system can be used strategically in conjunction with a backup system for the purpose of business continuity and some limited forms of restoration depending on the data and originating applications – note that most archives have the ability to write to multiple targets; and can be distributed; so you can easily achieve business continuity for the data and longer term data accessibility w or w/o replication.
However, it should not be considered to replace the restore requirements where you had a corrupt drive and need to restore yesterday’s data.
An archive is not a backup and visa-versa.
Good Luck,
Peter
July 2009