Direct-attached storage may be cheaper than network storage - say 20c a MB as opposed to 50 a MB - but can you use all of what you buy?
That's the poser from EMC's Australia and New Zealand head, Steve Redman (pictured right), who says the marketing battle between SAN - storage area networks, or sub-networks devoted entirely to storage needs - and NAS - network-attached storage, or a storage device attached to the network - is irrelevant.
The real issue, he says, is whether to go with storage networks, involving either NAS or SAN, or the old direct-attached storage approach (involving servers that also complete functions other than storage).
He gives the example of Kangan Batman TAFE (a technical and further education institution - similar to New Zealand polytechnics), in Victoria. It switched from direct-attached storage to a storage network. The TAFE had 5TB of direct-attached storage across a number of servers but only 800GB could be used because the storage couldn't be shared across servers. It implemented a switching layer between the storage and the servers and has increased utilisation to 90%.
Redman, who became managing director of the storage specialist this month, likens the NAS versus SAN debate to that of switch versus router in networking five years ago.
"Really, the answer was that we should all have been going to IP networks which included both switches and routers. It's the same here. [Instead of direct-attached] we should be going to storage networks - NAS for filing and printing and SAN for data warehousing and block data."
Redman accepts that the vendors drove the debate until they were able to offer both SAN and NAS. Now that EMC can offer both in devices such as the Chameleon it is pushing either option.
Redman says the network storage market is growing at 30% while sales of direct-attached storage are slowing. "Nine out of 10 deals we do at the moment are networking storage and you can get savings of up to 50%."
EMC, always regarded as a high-end storage vendor, is trying to push into the mid-tier market through its reseller relationship with Dell and has dropped its prices across the range, says Redman. He says that in the high-end Symmetrix range the cost has dropped 20% to 30% from 50 cents per MB, while mid-range Clariion prices are now around 10c to 20c per MB.
Redman says these days IT departments are getting the storage people involved right at start of an implementation.
"When you use an ATM [automatic teller machine] anywhere in the world, the information is stored with your bank in New Zealand but you can get it almost immediately. That information is 1000% available, totally centrally and totally shared. That's what storage should be like.