With 80 directly attached systems to upgrade, engineering
consultancy Arup chose a radical solution - to junk DAS and move
toward a single, tapeless solution. Candice Goodwin reports
From the Sydney Opera House to Gateshead's Angel of the North,
engineering consultancy Arup has provided the expertise behind many
of the world's most high-profile construction projects.
Its work is data-intensive - it is not uncommon for an Excel
spreadsheet model to take up 3Gbytes - and its data footprint is
growing 60%-70% year on year. Consolidating it all on a single
storage system has improved responsiveness and reliability while
making big savings on buying back-up tape.
As storage requirements grew during the 1990s, the 20-30 individual
departments within Arup's London operation had added extra
direct-attached storage (DAS) on a piecemeal basis. "It was getting
to be a management nightmare," explains global operations manager
Martin Cooper.
Furthermore, the systems were running out of space. It didn't take
long to conclude that simply replacing all 80 DAS systems with
higher-capacity versions was not a good idea. "If you have 80
boxes, it's hard to give them all enough care and attention with a
small IT department," says Cooper.
As well as management and performance, reliability was a live issue
for Arup. Recovering data held in its Exchange system had proved to
be particularly problematic. Failures were occurring every six to
nine months, with recovery times sometimes exceeding 24 hours.
"Our big problem with Exchange is that we couldn't easily verify
if the back-up was good until we tried to restore it - and then we
might find we were backing up from corrupt data," says
Cooper.
In 2000, Arup decided that consolidating all the storage for its
London office on a single tapeless storage device was the way to
go. Another possibility was to go for a storage area network, but,
as Cooper puts it, "laying fibre to do that would have cost more
than storage consolidation".
He and his team spent some time evaluating alternatives from a
range of suppliers, including Dell, EMC, StorageWorks and Network
Appliance.
The firm's storage technology needs were straightforward: support
for several terabytes of storage, an easy upgrade path and a data
snapshot facility for quick and easy back-ups. Data snapshots
facilitate near-instant online back-up by storing multiple,
read-only versions of each data volume.
Price was not an issue. Technology, however, was. Network
Appliance's approach to snapshotting was one reason why Arup
decided to go with its Nearstore solution. "Other suppliers do
snapshotting, but not as efficiently as Network Appliance," says
Cooper.
With 7,000 Exchange seats around the world, Arup is a major user
and liked the way Nearstore handled Exchange back-ups. It lets you
snapshot Exchange databases and will also verify the snapshot so
you know the copies are good. "You can restore to a known good copy
in minutes," says Cooper. "It saves all the grief of clustering and
mirroring."
Having decided to go with Network Appliance, Arup wanted to be
absolutely sure the new technology would work as billed before
rolling it out to the entire London operation. In late 2000, it
started work on an initial proof of concept, covering 600 staff in
its building engineering division, comprising eight separate groups
housed in three offices more than a mile apart and running 16
separate servers.
Over three months, all 16 servers were replaced with a single
Nearstore system linked to a back-up system using Network
Appliance's Snapmirror snapshot software.
The pilot system brought a number of important benefits. Many staff
found it much easier to recover lost data. It also means if someone
accidentally deletes a file they can now restore it themselves,
avoiding the embarrassment of having to ask ITfor help.
Recovery time for Exchange substantially improved: database
recovery in 25 minutes compared with 24 hours before. Storage
consolidation across the eight groups reduced the number of
back-ups by 90%. Merging eight mail domains delivered savings in
licensing, maintenance and tape media.
But possibly the most striking benefit has been the improvement in
resilience. "If the main box goes, you can fall back on to the
back-up box, but from what we've seen so far, the Nearstore systems
don't fail, so what we're really doing is protecting against the
building failing," Cooper says. The main and back-up systems are
kept in separate server rooms in separate sites.
Moving data from 16 servers to a single storage system proved to be
"amazingly simple". Arup used Network Appliance's Virtual File
Manager (VFM), which enables system administrators to create a
virtual name space for all files. Users can continue to access
their information as before while files are moved across in the
background.
The key to any move like this is meticulous planning. VFM allowed
Arup to do the planning in background. Two or three years along the
line, when the company has to start buying larger file servers, it
can just introduce new storage units behind the name space and the
users won't know the difference.
Network Appliance uses its own operating system, Ontap, which
handles mirroring, back-up and Exchange restore. "Having just one
OS is a lot easier, and with fewer than 100 commands, it's easy to
learn," Cooper says.
This summer, Arup started to transfer all 80 servers in its London
offices to Network Appliance storage, and is now about 20% through
the project. Performance across a network has proved to be an issue
with centralised storage, and for this reason most large offices
will have their own Nearstore server.
In London, Arup is installing a 32Tbyte primary Nearstore unit,
mirrored to two 48Tbyte secondary storage boxes, providing disaster
recovery and tapeless back-up.
Though Arup is investing more than £1m in its storage consolidation
project, Cooper estimates that it would have spent an equivalent
amount in simply upgrading its old direct attached systems - and
the new system is producing impressive savings. "The new tapeless
back-up system has paid for itself just by removing the need to buy
tapes," he explains.
But Cooper also expects to see benefits for the business. As well
as better data availability and security, Arup's compact IT team
will be able to work more effectively. "IT can easily regress into
a fire-fighting department instead of proactively going out and
working with the business," he says. "Rather than reducing the IT
team in numbers, we're expecting them to do better work."
Martin Cooper, global operations manager at Arup, is speaking
on consolidating and centralising storage capacity at Storage Expo
2004 on 13 October
www.storage-expo.com
This article is part of Computer Weekly's Special Report on
storage produced in association with Cisco Systems