News

posted on 28 August 2008 13:10

Extremely scalable storage supplier DataDirect has taken its existing sleep mode technology and branded it D-MAID, saying its dyamamism is better than the rigid static RAID schemes offered by Copan, EMC and HDS.

D-MAID, standing for Dynamic Massive Array of Idle Drives, can set drives into sleep mode, where platters and spindles are unpowered but the drive electronics still live, so that electricity is saved. It says the drives can spin-up in less than a minute whereas more than a minute would be needed if the drive electronics were powered down. Its arrays can have the sleep mode entered after a user-defined period of inactivity and the whole array, specific LUNS (logical units numbers or storage volumes assigned to applications) or designated sets of drives defined as sleep mode candidates.

DataDirect has three main S2A (Silicon Storage appliance) products:
- Entry level S2A6620 with mixed SAS and SATA drives and 120TB capacity,
- S2A9550 in performance or capacity-optimized versions using either Fibre Channel or SATA drives and topping out at 960TB in two racks,
- S2A9700 for real-time and archival data with SAS or SATA drives and a 1.2PB maximum capacity.

D-MAID can be applied to all three product groups although it makes most sense for the S2A9700, and it or a subset of its capacity can be set in sleep mode until a backup is needed.

DataDirect's D-MAID assertions won't wash when compared to Nexsan's AutoMAID though. Nexsan's Assureon storage uses AutoMAID technology and Intelligent Power Management (IPM) to power down inactive disk drives in steps so as to save power without compromising access speed too much. It can be applied to the whole array, individual RAID sets or individual drives. This is more granular power management than DataDirect's.

DataDirect Says...

A DataDirect spokesperson pointed out that: "In reality, Nexsan's offering is not competitive for large scale deployments or performance.  SAS is not available and 1.2PB of capacity -- which you can get in a single S2A system, with one management point for both high performance Tier 1 and archival Tier 2 storage -- would require 29 Nexsan systems. Do customers really want to take on that deployment and management challenge if they don't have to?"

 "Yes 'AutoMAID' supports three levels:

- Level 1 claims energy savings of 15-20% and sub-second recovery time.

- Level 2 claims energy savings of 35-45% and 15 second recovery tim

- Level 3 claims energy savings of 60-70% and 30-45 second recovery time.

"Contrast that with, for example, a S2A9550 system that DataDirect Networks recently tested at a customer site, which provides approximately 40 percent energy savings and 12 second recovery time."

^{[Chris Mellor.]}