The Server Room, Ars Technica's community for IT professionals, is sponsored by Dell's Future of Storage. This article is part of our ongoing series of topics and discussions related to IT and storage technology.
In this issue of the Week in Storage, analysts duel over green datacenters, products continue launching apace, and problems with Amazon's S3 service and HP's mediasmart servers see further explanation. A new "quasi-cloud" backup service launches, as new hardware continues to enter the wild. It has been another busy week in storage.
Home storage? Nah. Cloud storage? Nah. Home cloud storage? Killer.
Storage buffs have long eyed the proliferation of home servers—dedicated, expandable devices to fill home storage needs—with enthusiasm. The standard-bearers for this vision in the last year have been Microsoft's Windows Home Server OS and the OEM devices that run it, but there seem to be some problems. HP's Mediasmart line appears to have developed serious speed and accessibility difficulties after an HP software update on July 21. HP has acknowledged users' frustration and the existence of problems, and told users to reinstall updates manually. Some of those users report continuing problems, however. Clearly, HP still has to get some kinks worked out of its home server line.
Cloud storage may have kinks of its own to work out, if Amazon’s experience is any indication. Last week, Ars reported on an unpredicted 8-hour outage of Amazon's popular S3 cloud storage service. At the time, Amazon promised a full report on the outage, and has since delivered such a report. Evidently, while storage delivery communications are error-correcting, internal load-balancing communications between S3 servers were not protected. A minor error set off a cascading web of queries between servers, absorbing the entire S3 network in a frenzy of internal load-balancing communications which prevented them from processing external requests. In this case, cloud storage, supposedly decentralized and redundant, proved itself vulnerable through the very decentralization mechanism which protects it. Amazon says S3 has been immunized against this kind of failure, but the story of emergent cloud storage failure may not end here. Since similar systems guide many other such services, the unpredictable emergent behavior of these systems is justly the cause of some concern. Reliability difficulties may plague such storage services for a while.
Difficulties in cloud coordination may be eased by bringing the cloud into homes. This week, a startup called Cucku released backup software which stores encrypted copies of users' data on each others' computers. Two computers are paired, and data from each is encrypted and stored on the hard disk of the other, for recovery in the event of a failure. This service is subject to the typical difficulties associated with the poor upload speeds of home connections. A standard 384kbps ADSL upload would take almost a year of saturation to upload 1TB, so this service can't back up large amounts of data. Business users would have no truck with such a system, of course, so its application is limited to small amounts of essential data in the home. It is also a problem that two home computers so linked would both need to be on in order for syncing or backup to take place; unavailability of backup or restore capability is undesirable. Speculatively, if such a system could be centrally coordinated and decoupled from a pairing model, with each computer donating storage on uptime to the cloud and receiving distributed offsite storage back, such a system could remove hosting costs from cloud storage by shifting them to users.
Enterprise storage: is green the life or death of the industry?
Analysts dueled this week, as scientists move ahead with research into greener datacenters while another argued the green movement could be the death of enterprise IT. Scientists at UC San Diego are embarking on a major research project in attempting to reduce energy use in server rooms. The team will purchase a pair of modular server rooms holding some 500 servers, and test technologies for reducing energy use, including a novel data bus which uses less energy than fibre.
A paper in a SCSI industry journal's website argues that the greening of storage may be not the herald of a new era, but the death knell for the sector's riotous growth. Author Steve Denegri argues that potential for energy savings is limited, and that after it is exhausted, return on efficiency investments will go down dramatically, driving the industry to seek increases in power consumption for increasing capacity. And with power unavailable, the storage business will enter a decline. Markets will settle to a few established firms, and innovation will slow, as power is unavailable to support the industry's growth. The paper, which is a fiery good read, concludes that with the benefits of greening and virtualization tapped out by 2010, so that the industry will need vastly more electrical power, power which physically won't be available. "The cold, hard truth," Denegri enthuses, "is that an ample supply of energy is necessary to grow any business over the long-term, and the storage industry is shying away from the harsh reality that a sufficient amount of energy is, unfortunately, not available to keep the industry growing."
To whatever end: news about storage's uncertain future.
The IEEE this week approved a final specification for Firewire S1600 and S3200, new interfaces which allow transfer at a theoretical 1600 mbps and 3200 mbps, two and four times the speed of the current Firewire 800. This bandwidth is enough for at least three fast hard disks to saturate themselves. The new interfaces are backward compatible with older Firewire, and use the same plugs and cables. Daisy-chaining of devices will still be allowed. Firewire has been seeing decreasing use for a number of years now, and has largely been supplanted by USB2. This new standard, several months ahead of the release of USB3 and potentially competitive in speed, may allow the ailing interface to regain some ground. Controllers should appear soon.
A paper in Applied Optics this week described a new storage technology that could dramatically increase optical disk storage volume in the far future. Using a combination of exotic technologies and some fancy photoreactive acid-base chemistry in the disc, the team have created a disc capable of being written to, and read from, not on one layer or a pair of layers, but on several hundred layers, effectively storing data in three dimensions. Their proof of concept disc held some 200 layers, each at DVD density, which means a mature disc could hold 1TB in a DVD-sized disc to be read by a compatible computer optical drive. Upping density to Blu-Ray-level pit size could mean 5TB on one optical disc, but due to cost, complexity, and manufacturing difficulties, it is unlikely any commercial use of the technology will emerge for some time.
Hardware: external disks, internal NAND, universal bliss.
A number of new external storage devices launched this week, including:
A new line of cloud-backed NAS devices from Datto. The new devices use ZFS to manage a RAID0 or RAID1 set of two drives which are mirrored in real time across a network with Datto's own cloud storage, providing fault-tolerant on-and-off-site backup in one device. Datto promises to recover lost data within 24 hours, which presumably means physical shipment of media with lost data to jilted customers, since customers' internet connections won't transfer a disk's worth of data in 24 hours. All this hardware and service comes at a price; 250GB runs $500 and 1TB runs $1150, with service packages required to maintain the offsite cloud backup.A new "green" line of 3.5" external drives from SimpleTech. Encased in bamboo and carrying a $150 price tag, the [re]drive carries the same 500GB capacity and USB2 interface as thousands of other drives. However, its power adapter is more efficient than standard, its manufacturer claims, while packaging and materials were designed to be easier to recycle. Also, the drive itself evidently emits invisible "upscale rays" designed to lure design plaudits from tech bloggers. Either that, or it's a nice-looking drive.A new line of 2.5" external hard disks from Freecom. The new Mobile Drive XXS is a standard 2.5" drive in a USB interface, bus powered and sold in standard sizes like 160GB, 250GB, and 320GB, but Freecom has taken a novel approach to differentiating its product: size. That's right, this 2.5" hard disk is billed as the smallest such device, with 27% less case volume than its smallest rivals, and weighing less than six ounces. For those who care on size and aren't satisfied with smaller flash-based devices, paying $90 or $160 for what looks like a small rubber brick may be right in line.
Speaking of small, the Asus Eee is getting a third-party upgrade option for storage. Kit this week covered a new device from Buffalo which fits 32GB or 64GB of storage into the same direct PCIe interface slot ASUS uses for expanding the Eee's storage, and which allows Eee900-series users to drop $150 or $300 on a little extra space to make their learning, work, and play Even Eeeasier.