MAID: Where's the love?
Spin-down not a front-line requirement, for now
Will SSD take-up make MAID take off?
Macarthur thinks a kind of IT centre folk memory about never stopping disk drives is also pertinent. "I think data centre guys have a concern that if a disk does spin down they may face problems when it is spun up again. Dubious experiences in the past colour this. So it's better to let them keep spinning.
"As a result of these issues there is inertia around MAID products and their use has not taken off."
Will MAID mass adoption happen? Macarthur thinks that solid state drive (SSD) take-up could affect MAID usage: "Maybe the storage hierarchy in the long term - ten years - is SSD and tape." That leaves no reason for MAID systems to become solidly established.
Evans has a different view: "I expect MAID to be a mainstream feature in every array and the dedicated MAID players to lose out (eg COPAN, who will ultimately fail and get sold off as other array vendors implement their solution). MAID will become more complex - drives now offer variable spin speeds as well as spin down, so expect to see clever combinations of SATA/SSD with inactive data pushed to RAID groups which are then spun down - perhaps part of EMC's FAST?"
Which customers could benefit from MAID adoption?
Macarthur says MAID systems are a good choice where users have a clear view of energy usage by data centre devices, they understand the total cost of ownership (TCO) of MAID solutions, and they have the ability to clearly classify and move archival data. If the TCO is close to tape then well and good; if not then use tape.
Evans says MAID is good for "customers who need access to data online rather than tape... this offers a great solution to save some power. I'm not sure the power/cooling savings will be as large as some customers expect, however if the feature is free then it's worth having.
"There's also an unexpected saving in drive life - COPAN once quoted me a figure showing much longer life on SATA drives in their arrays.
"(It's) good for anyone with online archives or backups (but) probably best for enterprise customers as they will see economies of scale. It's also good for midrange customers if they choose to mix MAID within an array to power down archive data.
"On the negative side, ensuring inactive data sits exclusively on drives/RAID groups that can be powered down might be a challenge and the effort of achieving this (could) outweigh possible power-saving benefits.
The net of the two analysts' views is that drive array manufacturers will increasingly offer MAID facilities in their arrays but that adoption will depend upon the identification and monitoring of per-device power usage by data centre staff. MAID arrays may, as with Herefordshire Council, be bought as part of a wider data centre server farm virtualisation effort and their benefits lost within the more dramatic savings coming from physical server elimination.
Where there are specific archival data stores being purchased on a standalone basis then MAID facilities could come to the fore and swing the sale. That does not seem to be happening much in the UK yet but may increase as archival systems with a capable data capture, indexing, search, eDiscovery, compliance and retention monitoring capability feature set are taken up, driving sales of MAID archival data storage arrays forward in that area at least. ®