Future of Data Storage: 8 Technologies Changing Storage

From near term improvements in networking to longer term evolution in storage media, data storage is changing dramatically.

Data storage is undergoing dramatic evolution, in the near, medium and long term. The following new disk, solid state and tape storage technologies will offer enterprises cheaper, faster and more energy efficient storage.

Near term:

1) Ethernet hard drives
Seagate recently announced its Ethernet-connected Kinetic HDD, which the company claims will offer storage application performance that's four times greater than now possible.

Using Seagate's Kinetic Open Storage Platform it will be possible to do away with conventional storage servers and software and allow applications and hosts to communicate directly with disk drives over existing TCP/IP data center communications fabric using an open source object API. Each 4TB Kinetic HDD drive has two Gigabit Ethernet ports and can be accessed via its own IP address.

Costs associated with storage servers, software  (and their administration) will also be eliminated, while compute and storage will be able to be scaled independently, Seagate adds.

"If this storage architecture is commercially successful it will be extraordinarily disruptive since the direct connectivity from drives to applications will eliminate storage controllers, file systems, SANs and even RAID from the storage data path,"said Henry Baltazar, a Forrester analyst, at the launch of the Kinetic Platform last year.

The key value stores in Kinetic hard drives are a good fit for “object storage, distributed file systems (Hadoop Distributed File System, Lustre, GlusterFS) and distributed database (Cassandra) use cases," he added.

Seagate identifies object data storage, hyperscale and scale-out storage, cloud storage arrays and cloud backup storage as best-fit applications.

2) Helium filled disks
HGST, an independent subsidiary of Western Digital, introduced its first 6TB helium-filled drive in 2013. The benefits of filling a drive with helium rather than denser air are that it makes it possible to use more spinning platters in the drive – increasing capacity – and that helium offers less resistance to the spinning platters, leading to less heat generation and 23% less energy consumption, according to the company. 

Since helium-filled drives are sealed units, they can be used with highly efficient data center liquid cooling systems.

HGST has now introduced a 10TB helium-filled hard drive – leapfrogging Seagate's highest capacity enterprise hard drive, which is 8TB (and which does not use helium technology). And such is the promise of the technology that by 2017 all of HGST's enterprise drives will be filled with helium, and air-filled disk manufacturing will be discontinued, the company has announced.

3) Shingled magnetic recording (SMR)

Shingled magnetic recording is a storage technique that uses overlapping parallel data tracks instead of parallel tracks with a gap between them, as used by conventional drives. The benefit of SMR is that it allows areal density to be increased by up to 25%.

The problem with SMR is that when data is written to a track, all overlapping tracks have to be rewritten as well, and this means that SMR disks suffer from poor write performance. Both Seagate and Western Digital (and its HGST subsidiary) have been investigating SMR, but its adoption in commercially available products has been limited because of this performance issue.

Nevertheless, high capacity drives that make use of SMR are beginning to appear on the market. HGST's recently announced 10TB helium-filled drive uses the technology, but this is targeted at cloud and cold storage applications because of its relatively low write performance. If write performance limitations can be overcome, then SMR will give manufacturers a simple way to give areal densities a small boost before technologies such as HAMR (see below) become commercially viable.

Medium Term:

4) 60TB heat-assisted magnetic recording (HAMR) drives
Current high capacity hard drives use a technology called perpendicular magnetic recording (PMR), introduced in around 2005, to squeeze around 750Gb per square inch on a disk platter. Increasing areal density above this level risks bits reversing themselves spontaneously, leading to data loss.

But Western Digital and Seagate are both working on drives that use a technology called heat-assisted magnetic recording (HAMR) to replace PMR. HAMR uses a small laser to heat the part of the disk that is about to be written to. The effect is to allow smaller bits to be written to the disk, increasing the potential areal density to about 5,000 Gb per square inch. That means that 3.5" disk drives with a capacity of 60TB may be possible.

HAMR drives could appear on the market as early as 2016, but the first offerings are unlikely to offer capacities as high as 60TB.

 5) High performance phase change memory/NAND hybrid solid state storage.

Phase change memory (PCM) shows promise as an alternative to standard NAND (flash) memory used in solid state drives (SSDs). It uses a chalcogenide alloy in two physical states – crystalline and amorphous. Since the resistance of the alloy in the two states is different, this property can be used to store binary information. The physical state can be switched by applying heat, and as both states are stable they persist until they are actively changed.

State changes can be performed on a cell (and therefore data written) about a million times, which compares favorably with the typical 30,000 write cycles offered by high-end SLC  NAND cells found in enterprise class SSDs.

The problem with PCM is that it has a high write latency, but IBM has demonstrated that a hybrid device that uses PCM, NAND and DRAM on a single controller can work up to 275 times faster than a standard SSD device. This offers  read times of between 100 and 300 nanoseconds, and write times of between 10 and 150 microseconds.

IBM expects that storage products based on this hybrid PCM technology will be available in 2016.

6) New generations of Linear Tape -Open

First introduced in 2000, the current generation of LTO tape technology, LTO-6, offers 6.25TB capacity, assuming a compression ratio of 2.5:1, and costs about 1.3c per gigabyte or less. The next two generations will offer 16TB and 32TB respectively when they are introduced in the next few years.

In September 2014 the LTO Program Technology Provider Companies – HP, IBM and Quantum – announced an extended roadmap with two new generations of LTO tape: generations 9 and 10, with compressed capacities of 62.5TB and 120TB respectively. Transfer rates are expected to increase to rates of up to 1,770MB/s for generation 9 and 2,750 for generation 10.

As with all LTO standards the new generations will include read-and-write backwards compatibility with the prior generation as well as read compatibility with cartridges from two generations prior.

LTO-6 was introduced in 2012 and new generations of LTO tapes are introduced about every two to three years, so  LTO-10 is likely to be available in about 2021.

Longer term:

7) IBM 154TB tape

In May 2014 IBM and Fujifilm announced a new record in areal data density of 85.9 billion bits per square inch on cost-efficient linear magnetic particulate tape.  With that areal density, it should be possible to make an LTO-style cartridge that can store up to 154TB of uncompressed data, which is 62 times more than LTO-6 cartridges. The technology could be commercially viable in about ten years' time.

To achieve this high areal density Fujifilm has developed what it calls Nanocubic technology, which decreases the volume of individual Barium Ferrite (BaFe) magnetic particles without degrading their thermal stability. Low volume particles are essential for high areal density, while thermal stability is needed to ensure the long term storage capabilities of the tape.

BaFe storage has been shown to be reliable for up to thirty years in Fujifilm trials, and BaFe is also not subject to deterioration from oxidization since the particles are already oxides.

For its part, IBM has developed an enhanced write field head that can be used with the lower volume BaFe particles, and an advanced head positioning system that enables a track density 27 times higher than the current LTO-6 format.

8) Genetic storage

Scientists routinely sequence woolly mammoth DNA that has been kept cold for thousands of years, so there's no question that the storage medium can last a long time. And scientists in the UK demonstrated last year how DNA can be used to store archive data that can be read back with 100% accuracy.

The DNA molecule is also a very dense storage medium, so one gram of DNA may be able to hold 2000TB of data.

At the moment DNA synthesis is far too expensive to use DNA data storage commercially, but in the future it could be viable for long term archiving of government data and other information that needs to be archived long term for regulatory compliance purposes.

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