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Nexsan already supplies a de-duping MAID-based VTL.

When I did my mental back-of-an-envelope speculation about combining de-duping and MAID (massive array of idle disks) to get both terrific capacity and reduced storage energy costs I didn't realise that Nexsan was ahead of me. Brendan Kinkade, the company's VP for marketing, has sent me this note:-

"In the 4.x release of the product (currently shipping) we use a single instance storage technique that stores only one copy of the bits. Each storage request produces a unique metadata file that describes the file. This permits each storage instance to have different file names and retention periods, while removing all duplicate files. Each metadata 'points' to the same 'bit collection.'"

What this means is made clear in a statement off the Nexsan website: 'Assureon's secure storage is based on a single-instance content-addressed storage (CAS) model, ensuring that only a single copy of a data object is stored in the system, dramatically reducing capacity demands and bandwidth requirements and significantly slashing customer costs.' Only one copy of a file gets stored. What's coming is sub-file level de-duplication.

Kinkade continued: "In the 5.0 release, currently in development and scheduled for release in early '07, in non-compliance mode, we will de-duplicate the file in 32K or 64K blocks."

"That is, each block will be treated as a separate 'bit collection' and we will de-duplicate at the block level. The de-duplication will take place both on the wire (compliance and non-compliance modes) and in the actual storage. The block level de-duplication will speed up the 'archive' time for files that are under version control (databases and other very large files)."

"Wire-based de-duplication will be in the 5.0 release. Block level de-duplication storage will be visible in the 5.1 release."

It's probable that, at the moment, Nexsan has the most space-efficient and lowest energy cost VTL disk storage available from any vendor anywhere. With Assureon V5 it should definitely be able to claim first place in the energy cost-optimised high capacity VTL stakes.

Tape is so-oo green

Hewlett Packard is singing the tape-is-green song as seen in Duncan Campbell's blog. Duncan is w-w marketing boss for HP's StorageWorks.