You may have ten times more data to store in five years' time than
you do now. Jane Dudman looks at your management options
The price of storage per Gbyte has plummeted in the past few
years, but not the cost of managing it. Volumes of stored data are
set to rise - as more business is conducted over the Internet, the
volume of information being captured soars. Analyst company
Forrester Research says that most companies will have 10 times more
storage in five years time than they do now. Forrester thinks that
will push up the amount being spent on storage and the
administration to run it, from 5% of today's average IT budget to
17%.
"The cost of managing storage is anything from four to eight
times more than the cost of buying it," says Paul Gunstone,
director of e-continuity at disaster recovery specialist Safetynet,
a major user of Legato storage software. Gunstone believes the real
costs of managing storage is bringing about major change, as
companies re-assess their storage strategies in the face of new
technologies.
As a result of the reduced cost of storage media, the cost of
building mirrored systems has fallen dramatically. This can have a
big impact on overall costs by allowing changes to be managed
within normal working hours. Gunstone cites one company that saved
£20,000 in overtime costs after installing mirrored systems."With
mirrored systems, rather than having to wait until out of hours to
carry out upgrades, the IT team can take down one system and
resynch it, then do the other."
Another way to cut down the cost of managing storage is to
consider outsourcing, which has not yet impacted storage, except as
part of an overall IT contract. For example, US firm
StorageNetworks, whose service is based on providing fibre-based
connections from its storage centres into customer premises, has
built its first UK centre and is building a second, with the
infrastructure due to be in place by the end of March.
Safetynet is working closely with StorageNetworks and Gunstone
says outsourced storage will provide customers with much greater
financial and technical flexibility. "This is a managed storage
service," he comments. "At its lowest end, it's disc on demand. You
buy a processor, phone the storage management company and say you
need an extra 50Gbyte of storage. All they do is turn up the
tap."
The financial advantage of a storage service is that it turns
the capital cost of buying storage into ongoing revenue costs. In
the US, StorageNetworks charges around $65 (£41) per Gbyte of
storage per month, so it will pay IT managers to work out what they
spend on purchasing and managing storage. Initially, though, this
kind of service will be economical only for fairly large customers,
acknowledges Gunstone.
"This service is based on dark fibre and that is still
expensive," he admits. There are other limits too: customers will
have to be within 25 miles of a StorageNetworks centre to use the
dark fibre links, although the facility can be used over a WAN from
anywhere in the country.
Internet-based online storage is based on a similar concept to
managed storage services, where the storage facility itself is
off-site and run by a specialist company. Several companies, such
as NetStore, now sell online storage services and claim to be able
to provide services for both large and small customers.
Most IT managers still run their own storage facilities in-house
and are looking to make the best use of new technologies,
particularly the much-hyped concept of storage area networks
(Sans)tohelp them face the familiar challenge: how to enforce a
regular, efficient back-up policy for all systems, particularly
when it comes to remote and mobile users, and how to ensure users
can access stored data quickly when they need it.
Ian Batten, principal systems engineer at Fujitsu Telecoms
Europe, which uses storage systems from Auspex, says his company's
storage requirements have soared over the past decade. "The main
requirement when we first bought storage systems was performance,"
comments Batten. "Back then, we had about 30 or 40 users on
disc-less Sun workstations and we wanted to get data onto the
desktop in the minimum time. Now we have more than 1,000 users and
a more heterogeneous environment, so the emphasis of our storage
strategy now is on space rather than speed."
Batten says today's combination of communications and storage
systems should be able to provide the performance levels required
by most businesses. "There is a finite amount of data people need
at any one time and that has not expanded as fast as you might
think," he says. "You can buy any fileserver and get a reasonable
performance, unless you have extreme requirements like the oil and
gas industry. But what you do need is capacity."
Fortunately, he points out, the cost of storage has plummeted as
demand for capacity has soared. The first storage system Fujitsu
Telecom Europe bought from Auspex was a 14 Gbytes system. The
company pays the same price for 2Tbytes storage now as it paid for
14Gbytes then. "The price per Gbyte has dropped to not much over
£100," points out Batten. This makes it easier to buy larger
systems, but gives managers like Batten bigger headaches about how
to manage such large facilities.
In the debate about whether storage should be split up and kept
close to the systems it is supporting, or kept as a central storage
facility, Batten is firmly on the side of centralisation. "It is
good to keep it in one place because it makes the back-up transfer
easier and, in practice, the meantime between failures is better
because the chances are that most of the users need most of the
servers most of the time," says Batten.
Other organisations feel differently. The British Library, for
example, has installed a storage system based on multiple storage
servers partly because supplier Mosaic feels this reduces the
potential for a single point of failure.
Whether IT managers opt for centralised storage or a more
dispersed approach, the real key to managing storage effectively
lies in software. Hence the rise of storage software specialists
such as Legato and Veritas, whose products are used by many of the
leading storage suppliers.
The importance of storage software is acknowledged by Michael
Tonge, technology project manager in PruTech, the IT services
division of insurance giant Prudential Assurance. Prudential has
installed systems from storage specialist EMC to back up its huge
Oracle customer contact management database, available online to
the company's 90 regional UK offices. The software it uses includes
EMC's SRDF and TimeFinder, which help create real-time mirrored
volumes of the Oracle databases, and Enterprise Data Manager
software, which backs up mirrored data from an EMC Symmetrix 3930
server to StorageTek tape libraries.
"The resilience provided by the Symmextrix hardware, in tandem
with the SRDF and TimeFinder software, ensures bullet-proof,
non-stop operation," comments Tonge. Not only is the Prudential
looking for full resilience, it also wants to be able to carry out
its back-up procedures with the least possible interruption to its
business operations, which is a challenge when running a 1.5Tbyte
customer database.
TimeFinder and SRDF are used to run point-in-time back-ups,
enabling business-critical activities to continue while backups and
restore operations are being carried out. Mirrored volumes of the
database are created, then split from the production system and
used for non-disruptive point-in-time back-ups. After the back-ups
are completed, the mirrored volumes are synchronised with the
production system. By carefully timing back-ups, data can be
restored almost instantaneously from the mirrored system for more
than half the working day, while online database transactions run
uninterrupted.
Not many businesses have to cope with the huge storage challenge
faced by the Prudential. But whatever their size, organisations
have to ensure they have the right systems in place to back up and
access all that information. If storage requirements grow as fast
as many predict, the hitherto overlooked cost of managing storage
is going to become a hot potato in many IT departments.
Cutting the cost of storage management
- Media is cheap, management is not. Mirrored systems enable more
work to be done in office hours and cuts expensive IT staff
overtime bills
- Managed storage services and online storage are emerging as a
potential alternative to running in-house storage and turn capital
costs into revenue costs, but need careful assessment
- Watch the footprint: large central storage systems may take up
large amounts of premium price floorspace; but with dispersed
systems, watch out for the comms costs
- Watch out for hidden hardware upgrade costs, such as moving
from CD to DVD
Centralising storage
There are a number of storage management benefits to be achieved
by moving to a large centralised enterprise class storage
subsystem, says Tony Reid of Hitachi Data Systems.
Raw storage costs - By consolidating storage requirements
into an enterprise storage subsystem the spare storage pool can be
allocated to the busy servers, leading to better utilisation of
storage resources and reduced costs
Reduced management costs - One centralised enterprise
storage system means only one management structure. Research group
Dataquest claims that one person can manage three times more
storage if it is centralised versus distributed
Availability - Centralising storage with an enterprise
system from one supplier allows the user to take full advantage of
their business continuity features
Scalability - To achieve this benefit an organisation
needs to link its centralised storage to a storage area network
(San), freeing up network resources by taking back-up traffic off
the Lan.
Managing storage at the British Library
One of the benefits of the British Library's move to its new
site at St Pancras has been a decision to consolidate its store of
book titles into a single central database of titles on CD and DVD
disks, enabling the public to access digital reference material in
the library.
The library wanted a reliable system for the half-million
researchers who use its facilities each year and, equally
important, the ability to add new titles. Each year, the library
adds more than 500,000 new items to its collection and expects that
number to rise sharply as a result of the growth in new media and
digital reference titles. It wanted a storage system that was
physically small because, despite the move to the new site, there's
still a shortage of space, and was cost-effective to buy and
manage.
The library opted for a system from Mosaic Systems, based on a
multiple server approach. It has installed ten storage racks, each
containing an Axis StorPoint CD E100 server, six CD-Rom drives, one
DVD drive and a 36Gbyte hard disc drive and is using mirrored
caching. Not only does this ensure almost instant access to the
stored titles, but also ensures compliance with CD and DVD software
licence rules, which could be potentially infringed by copying data
to a hard disc and physically removing the media.
Mark Davies, digital media development manager at the British
Library, says the result is a marked improvement on access to the
CD-Rom titles. One particularly useful feature has been information
from the system about CD and DVD use, enabling managers to ensure
they have enough licences for the titles in most demand.