Unisen Inc. had five servers running software for back-office services it provides to Canadian financial institutions. The Mississauga, Ont.-based company used multiple boxes because it was uncertain the technology was robust enough to support all its clients from one machine, says Robert Smuk, Unisen’s

president. But five machines were harder to manage and support than one, and dividing the workload interfered with allocating power to whichever client needed it most at the time.

Unisen set out to consolidate from its five servers to one machine. The consolidation is nearly complete, Smuk says, with about 95 per cent of the workload now on the new larger server. Of course business continuity remains a concern, so Unisen has a backup server ready to take over if there are problems with the primary one.

Server consolidation is getting lots of attention these days as cost-conscious IT shops strive to squeeze more from their resources.

“”The driving force behind it is trying to become more efficient,”” says Alan Freedman, research manager for infrastructure hardware at IDC Canada Ltd. in Toronto.

The case for consolidation has been strong for some time. Server utilization rates are often as low as 15 per cent for smaller servers based on Intel Corp. chips, says Gordon Haff, senior analyst at research firm Illuminata, Inc., in Nashua, N.H.

“”It’s almost become a cliche that server utilization is terrible,”” Haff observes. Cheap hardware has encouraged installing a new server for every new application, and hardware has gained power faster than many applications increased their processing demands.

Unisen is an exception to the utilization argument — Smuk says utilization of the new, larger system is about the same, at around 70 per cent, as utilization of the five older boxes.

But he says Unisen saves money because the single server is easier to manage and more flexible.

Trying to cram too many applications on one server is a mistake, Haff warns. Servers can reasonably run at 50 to 75 per cent of capacity if loads are fairly constant, he says, but remember to allow for peaks.

Dan Ryan, manager of IT infrastructure and desktop management at the City of Calgary, knows all about that. A couple of years ago, the city consolidated its building permit application, geographical information system and PeopleSoft software — “”probably three of our top five applications”” — on a single server.

“”We were able to physically get it all on a single server,”” Ryan recalls. “”The downside is, we were having all kinds of peak performance problems.”” Those applications now have their own servers again, but Ryan is now consolidating the city’s 140-plus Unix servers. Having learned from experience, he is taking care to combine applications whose processing needs peak at different times, and aiming for 30 to 40 per cent utilization, leaving comfortable headroom.

Haff says some savings from consolidating servers should be invested in making those that remain more reliable.

“”If you do everything right, you could then have a more reliable system than you had before,”” he says. “”If you don’t do those things, you’re opening yourself up to more expensive failures.””

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