Outsourcing your storage can provide a cost-effective
solution to the increasingly tricky problem of data management.
Danny Bradbury investigates the options and assesses the risks and
rewards
Back in the heady days of the late 1990s, storage outsourcing
looked like a big market. The idea of taking storage outside the
company and placing it in the hands of a shared storage provider
was attractive, because it removed an infrastructure headache from
the IT department's hands and allowed IT managers to get on with
planning new projects. However, companies such as Storage Networks,
which helped pioneer the concept, failed because the market did not
grow as quickly as it had hoped.
But outsourced storage still offers opportunities for IT managers
interested in managing their storage needs more effectively. Some
companies offer primary storage as an outsourced resource, meaning
you can connect your applications to a drive at a remote
site.
"BT has never abandoned the shared storage provider model," says
Correy Voo, head of storage services at the telco. BT offers both
types of storage solution, but he says that many applications are
not built to deal with primary storage mechanisms located miles
away. A core Oracle application can probably be made to work with
such storage, but in industries such as finance, where highly
customised applications are built on top of a database engine,
connection latency can become an issue unless the code is
configured properly. For high-data, low-latency requirements such
as audio and video editing, Voo says it is better to keep primary
storage in house.
Primary storage is limited to being within a metropolitan area
network, says Stephen Holmes, head of the technology directorate at
outsourcing firm Atos Origin. He adds connectivity costs to Voo's
latency concerns. As distances increase, companies not able to use
fibre connectivity can look at multi-protocol label switching
(MPLS) to help increase quality of service.
The other problem lies in integrating the provider's storage
mechanism with a server infrastructure, says Voo. "We will nearly
always encounter situations where a customer does not like our
flavour of storage, or where there are incompatibilities." This
will be especially true when trying to connect to San environments
using IP-based versions of high-end connection technologies such as
Fibre Channel and SCSI. Voo highlights Fibre Channel over IP as a
potential integration challenge, and other service providers
express similar concerns about iSCSI, the IP version of the SCSI
connection protocol. Voo believes that SMI-S, the storage
management compatibility standard promoted by the Storage
Networking Industry Association, could help solve some of these
issues.
For this reason, most people dealing in outsourced primary storage
tend to outsource the applications as well, so that the storage and
the application can be kept closer together. Service provider Star
Technology outsourced the storage for a legal client's document
management system, but hosts the document management software on a
server in the same datacentre, says strategic technology officer
Dan Scoble.
With outsourcing primary storage is still largely a niche
application, outsourced back-up still presents peace of mind for IT
managers. Storage services company Iron Mountain launched two
electronic vaulting services in the UK this year, says business
development director Jon Fowler - one handling PC desktop back-ups,
and the other looking after the server. On the desktop, its
client-side software initially synchronises the desktop data
(something best done over a weekend or via a physical CD transfer),
and then updates the back-up iteratively, sending changes on a
byte-by-byte basis every day.
The company solves the problem of intermediate connections when
using laptops by including a facility to automatically start a
back-up on connection, including a resume feature to pick up
whether back-up left off should a connection fail. All uploads
happen in the background.
Software is encrypted before it leaves the desktop, he says, and
because ongoing back-ups only handle file changes, the bandwidth
needed is relatively small. The same goes for the server product,
which works in a different way. It works on a continuous back-up
basis, almost like server mirroring, but again deals with
byte-level file changes. With file compression, it reduces the
strain on the network.
Josh Krischer, regional vice-president of research in enterprise
servers and storage at analyst firm Gartner, says the marketing for
outsourced primary storage is of limited value. "The cost of
telecommunications is higher than the cost of the storage," he
says. He prefers the idea of managed storage, in which storage
devices are located at the customer's premises but owned by a third
party.
Either way, letting someone else handle storage can be a positive
step, because companies do not always want to invest in capital,
sometimes preferring to log operating expenses rather than capital
expenditure. Moving to a managed storage business, possibly by
entering into a leaseback agreement with your own storage devices,
can allow this to happen.
When considering outsourcing either the primary storage system or a
back-up system, be sure to think about the service level agreement.
Most suppliers offered a 99.99% availability guarantee, although
response times are less certain because some offices may be
accessing remote storage systems via non-dedicated, public
links.
Also consider pricing. For its primary storage outsourcing service,
BT charges on a per-gigabyte or terabyte-per-month basis with the
price varying according to the type of back-up protection. Iron
Mountain charges a flat fee every month on a gigabyte per-seat
basis for its desktop PC back-up service, and on a per-gigabyte
basis for its server offering. It only charges for the original
file stored, rather than for subsequent changes made to that data.
If a file changes numerous times, it would store new versions of
that file based on the changes received, but will still only charge
for the space taken up by the original version. "Unless the client
has a 90% change rate, which is rare, it is pretty much covered,"
Voo says.
Like the ASP market, which is being reborn as managed services, the
storage service provider market suffered from a tarnished image
after the dotcom bubble burst. But there are enough companies still
offering the service to prove that it is still viable, and IT
managers could benefit from taking another look.
Outsourced storage checklist
Your corporate data is one of your most precious assets. Before
handing it over to a third party, there are some questions you
should ask. Here are five that should be at the top of your
list.
Is your motivation technical or
financial?
If you want to move your storage costs
from the balance sheet to the profit and loss sheet for accounting
reasons, there are other options such as a lease-back agreement on
your existing storage equipment.
Management or extra resilience?
If you
are considering outsourcing to increase resilience, off-site
outsourced storage is a good idea. If reducing management costs is
your objective, consider maintaining the equipment on your premises
but having it managed by someone else. This will eliminate telecoms
costs.
What are the pricing options?
Having a
pay-per-use utility storage agreement is attractive if you have
volatile storage requirements and it may reduce your footprint from
one month to another.
Primary or back-up?
Outsourcing primary
storage or mirroring your primary storage in real time gets very
expensive. Is this what you need, or do you simply want to transfer
data in batch mode to a secure off-site location?
What is the application?
If you are
replicating primary storage to an outsourced server or outsourcing
primary storage altogether, your application is a key concern. Is
it heavily customised with lots of complex code, or is it
relatively simple with straightforward read/write capabilities and
little extra processing of analysis? This will affect latency
issues.
Case study: Atoc speeds up the accounting
cycle
There can be few things more complex than the accounting system
for a privatised rail network. The Association of Train Operating
Companies (Atoc), which represents the private rail franchise
holders, needed to revamp its accounting system. The Rail
Settlement Plan, an Atoc subsidiary which runs the accounting
system, recruited Atos Origin to develop Lennon, an outsourced
accounting system that would help the company move from a four-week
accounting cycle to a daily one.
Storage was a key issue from the start of the project. The
system has to process roughly one million customer transactions
every day, using a complex set of business rules to work out how
much of the revenue from each transaction is given to each of the
rail companies participating in that particular journey. The
transaction processing, which is done in batch form between 8pm and
5am every night, produces output data used to populate a
datawarehouse. The datawarehouse should reach 5Tbytes at its
seven-year point, says Adrian Hepworth, Atos Origin's technical
architect for the project. The storage requirement for the system
was huge, because as part of the 2001 contract, the company had to
store all data for the lifetime of the contract.
The firm uses a Hitachi Lightning 9960 Raid array at one set of
offices, and a 1Gbit link is used to mirror all the data to a
secondary site 125km away. The systems offer 15Tbytes of storage
between them, which is enough to handle the datawarehouse and the
transactional system together. But operational constraints are a
problem. "A 1Gbyte link only gives you 200mbps through it, so it is
a challenge getting 1gbps of data down a Gb link," says
Hepworth.
The company uses an IP link to connect the two sites with
Veritas Database Editions and Veritas Volume replicator. Mirroring
discs at the disk level rather than the application level with an
IP link enables the company to use it for anything else necessary,
such as FTP sessions, for example. "
To help reduce storage requirements, Atos Origin uses the
Analytic Server from Sand Technologies. Analytic Server is data
management software that uses bitmapping techniques to compress
database data and enables the company to store historical records
on primary storage, rather than taking them off to tape or optical
storage.
"Because of the compression, we can take 100Gbytes of data and
store it in two," says Hepworth. "That means our cost of storage
has gone down to 5% of the original cost. And we get the cost
savings without having the headache of taking the media
offline."