What new technologies and systems are emerging to help IT managers
cope with the ever-increasing demand for storage? Nick Langley
finds out
How do you plan and develop for the future when present storage
requirements are a fast-moving target? With the demands of
e-commerce and multimedia, many organisations find themselves
doubling their storage every year just to stand still. Yet within
most organisations, there's already a lot of under-utilised
storage, and much of the new media purchased each year is destined
to be used to, perhaps, as little as 30 per cent of its
capacity.
One answer is better storage management, tracking down the
capacity that is under-used, while monitoring the loads on busier
servers, to ensure a proper balance across all available media.
Hence the trend to central consolidation of storage. But without
standards, which make any storage available to any device that
needs it, much capacity is going to remain locked away. Much
dedicated server attached storage remains inaccessible to other
devices. Even on network attached storage, servers are essentially
coupled to proprietary storage from the same manufacturer, or at
best confined to the same operating system.
Overcoming these problems is the promise of Sans, with
intelligence provided on the San, by products like Tivoli Storage
manager.
Sun's storage marketing manager, Chris Atkins, says that if Sans
are to be the de facto way of providing storage, they have to pass
the Lan test. 'On Lans you don't have hardware and software
coupled; you're not confined to the products of a single vendor.
The opposite is true in storage at the moment.'
Sun's most significant current development is Jiro. It is
intended to ensure that all storage devices are used to the full.
'Jiro defines the APIs between software bits and pieces, putting
Java wrappers around storage devices, such that they can all
communicate with one another in the same way,' says Atkins.
He stresses that like Java, Jiro is not a product, but an
initiative which Sun hopes will be taken up industry-wide. The
agreement of the specification is out of Sun's hands, and within
communities of suppliers and users. Atkins expects the standard to
be ratified by the end of Q1, 2000, and a number of companies to be
shipping Jiro-compliant products by the end of this year.
When standards take over, customers won't need to buy from array
suppliers, which essentially manufacture storage products to
proprietary standards. 'Currently it's not worth Sun, or IBM, or
EMC, going into solid-state disks, because the market's too small,'
says Atkins. 'With SAN standards, the market potential will be
realised by the technology developer, not a middle-man.'
The real issue is not how to supply storage capacity to meet
growth, but how to manage the growth, says Tony Reid, storage
solutions manager at Hitachi Data Systems. 'With a lot of NT
servers with directly attached storage, only 30 per cent of
capacity is being used, yet other servers keep running out of
storage. The answer is to consolidate the storage - or attach it
all to a SAN where all storage would be accessible by every server.
If it doesn't happen, within three years most organisations won't
be able to cope with storage access and backup requirements on the
Lan.' Reid believes that with the standards coming from the Storage
Network Industry Association, we'll have plug-and-play storage in
data centres by the end of this year.
According to Robin Pilcher, Tivoli's European marketing manager
for storage management, up to 60 per cent of Lan traffic currently
is backup, archiving, disk space management - work that is
essential, but not productive. This will move to the SAN. The SAN
will have the intelligence to manage all storage related tasks,
taking the load off application servers. 'More than half a web
server's cycles can be disk housekeeping,' he says.
Tivoli talks about information management, rather than storage
management - the free movement of any data across the enterprise,
to wherever it's needed.
There's an 'aggressive' plan for rolling out enhancements to
Tivoli Storage Manager for managing information and the SAN. All
modules can be used in stand-alone mode, or be integrated, and all
use a common interface which is web-browser based, and so
manageable from anywhere.
Tivoli Storage Manager has been radically transformed from ADSM
(an IBM storage management product), which quietly disappeared as a
product name before Christmas. Also just before Christmas, IBM
acquired SANergy, which will provide the base for Tivoli's data
sharing capability.
'It's possible today to have data sharing using SANergy,' says
Pilcher. AIX, NT, and Solaris can all access exactly the same data
file, instead of needing multiple copies.
Storage management requirements are moving beyond the firewall,
with the need to support service levels along supply chains, and
'pervasive computing' using laptops, handhelds, and mobile phones.
For the supply chain, or business to business support, there's
Tivoli Cross Site, which Integrates with Tivoli Storage Manager for
the storage-related elements of service - every transaction at some
stage is going to require data.
Tivoli Storage Manager client can be installed on laptops, and
other mobile devices. This has the intelligence to do, for example,
backups in a way appropriate to the link to the Lan or SAN, without
interfering with the work the user has logged on to do. If the user
has linked via a phone line, only changed bytes would be backed up.
If on a network, backup would be at block or file level. So-called
Adaptive Differencing is also used for backing up devices on the
enterprise network.
Tivoli supports Lan-free data movement over the SAN now.
Server-free data movement will be added later this year. By the end
of the year, much more sophisticated data sharing will arrive,
allowing data to be shared across many different platforms.
Meanwhile, storage media manufacturers are rising to the
challenge of annually-doubling requirements. In the first seven
years of the '90s, storage density on hard disks doubled every 18
months; now it's every 12 months. The first high specification PCs,
affordable only by power users in businesses, had 20 Megabyte hard
disks. Now parents buy their children 600 multimedia PCs with disks
measured in tens of gigabytes.
Sooner or later, we will hit the limits of current magnetic
media technology. R&D white papers from storage developers are
already talking in terms of bits being stored at the molecular
level, and the search is on for 'frontier materials' - alloys with
smaller molecules to increase the storage density still
further.
IBM's Zurich Research Lab has come up with an alternative
high-density storage, using mechanical components derived from
atomic force microscopy (AFM), a technology developed by IBM. It's
been christened the Millipede, because it uses arrays of 1000-plus
legs, or tips, on cantilevers etched in silicon. Tiny indentations
poked into a polymer layer by AFM tips represent stored bits that
can be read by the same tip. IBM believes it's possible to reach
storage densities of up to 80 billion bits per square centimetre,
five to 10 times more than the expected limit for magnetic
storage.
A research prototype of the Millipede has already demonstrated
the feasibility of this new approach to ultra-high density storage.
Low energy consumption and wear is less of a problem than with
large mechanical systems. And, like silicon chips, nano-mechanical
devices are suitable for batch production.
The remaining challenge is to ensure that Millipede can read and
write data fast enough to be practical. Parallel operation of 1024
tips could make possible data movement rates of more than
100Mbits/sec. The medium can be erased by heating up the polymer,
and restoring it by a reflow process. Bit-level erasing isn't
possible, but IBM says this is not required in most
applications.
Peter Vettiger, who leads the Millipede research, says
thermomechanical data storage may go well beyond the density of
magnetic storage technology. 'However, our work is still in the
early stages of development, and the use of a polymer as the
storage medium is only one of several possible solutions. If the
required functionality can be integrated into cantilevers and tips,
the Millipede concept may become a universal read/write device for
future storage systems.' Vettiger adds that devices only a few
centimetres or millimetres across, will open up new possibilities
for integrating computer power into small 'pervasive' devices,such
as video cameras, mobile phones, and watches.
On the magnetic media side, IBM has achieved 35.3 Gigabits per
square inch,almost double the 20 Gigabit record it set earlier in
1999. This was enabled by development of a new metal alloy disk
coating. As bits are made smaller, they tend to lose their magnetic
orientation over time. The movement of atoms at room temperature is
enough to flip the polarity of a bit from 0 to 1. IBM claims bits
written onto the new material have the same stability as
lower-density disk drives already on the market. John Best, vice
president of technology at IBM Storage Systems Division, says disks
with the new coating can be made commercially, using existing
equipment.
The one terabyte hard drive is on the horizon. Within a decade,
with new magnetic alloys and handling techniques, we could be
looking at disks with a density of one terabyte per square inch. A
3.5 inch platter on a desktop PC's hard drive would hold nearly 50
gigabytes, and a 2.5 inch disk on a notebook 20Gb-plus. Since a
single drive can hold as many as 10 platters, those figures could
be multiplied by 10.
Magnetic tape has had the last rites read over it more often
than the mainframe, but like the mainframe, it continues to evolve.
Last May IBM's Removable Media Storage Solutions Development Lab in
Tucson announced what was then the highest storage capacity in the
tape storage industry: 100 gigabytes of native,uncompressed data on
a single Linear Tape Open (LTO) Ultrium cartridge (see box).
Already tape stability is assured. SLR (Scalable Linear
Recording) tape stored correctly carries a lifetime guarantee. DLT
manufacturers promise 30 years shelf life. These figures are
extrapolated, since the technologies haven't been around that
long.
As the technology moves from megabyte to terabyte capacity, the
physical attributes of the tape drives will change.