Part 1 of this article can be found here.
The best consolidation platforms can accommodate some kind of hardware and software partitioning because the applications -- and the users -- sometimes require finer degrees of separation, users say.
For example, HP's Superdome uses hardware partitioning, which enables Continental to keep each department's applications separated. This makes each group more comfortable with the consolidated setup. "We install everything and do things like failover for the whole box, but at the [operating system] level, the groups own their applications and they're all kept completely separate. And that's the way they like it," York says.
At the financial services firm, Bradley uses a mix of hardware and software partitions to accommodate different applications. "Some applications work just fine in a VMware environment," where processing power is carved up virtually using the software, he says. "But for a seriously [network-intensive] chatty app, a blade server is a better fit." This is because blades use their onboard switching capabilities to provide an extra layer of separation that's not possible in a strict VMware environment, he says.
Of course, consolidated servers do have their downsides, users say.
Scheduling can get dicey, for example. Patching the operating system for the primary server is easier than patching across multiple servers, but it could mean bringing down all the resident applications at the same time. "With 24-by-7 ATM machines and a variety software, anytime we want to bring a server down, it almost requires an act of God," Bradley says. "Nobody can agree on the best time."
Bradley says this problem might get solved when he moves to VMware ESX Server 2.5, which became generally available in December. "It lets you move your VMware sessions off one box and onto another just by dragging and dropping. So you could patch your [operating system] on one machine and drag it back without affecting anything, which is nice," he says.
Continental's York follows a similar protocol, patching systems every time he does a failover test for the Superdome environment, a task he schedules quarterly. Patches for critical holes are done as needed.
"Firmware upgrades have been the biggest hassle. The complex thing about a consolidated server or storage environment with the firmware is that there is a dependency chain. If a tape library needs a certain firmware, well, you better make sure that firmware is also compatible with everything else you're running. It's all more complex," he says.
Backups also are sore spots, Bradley says. The VMware environment initially caused problems for him because every time the backups ran on the various applications on the box, it brought the server to its knees. VMware is aware of this problem and has posted a series of fixes and workarounds, one of which is using background Perl scripts to create back-up snapshots.
"We were able to build a Perl script to kind of stop and start the server," Bradley says. "Rather than run a tape backup within each VMware session, we stop it, take a snapshot of that file, and then start it again. It gives us a full backup of everything on that box and on the VMware session, and it's much faster. It doesn't drag on the CPU and utilisation."
Perhaps the most important piece of advice users offer is to choose your consolidation platform wisely. Make sure it's large enough. "You should always buy the biggest and the best hardware you can afford for this. You really can't overprovision because the more you provision, the more you can do," Bradley says.
Another tactic is to get a pay-as-you-go deal from your vendor. "That's the best way," Olaf says. "In our consolidation project, with the first application of the SAP system, we didn't need all 48 processors of the machine -- and we didn't pay for it. But as we increased the number of applications, we could increase the number of processors, on a pay-as-you-go basis. It was very flexible and cost-effective."
Users also should understand the road map for the vendor platform on which they're consolidating. Because HP uses cell board technology, the Superdome is plug-and- play when it comes to processors, Continental's York says. Each Superdome supports as many as four cell board modules, each of which can be configured with one to four PA-8800 processors. As the need for processing power increases over time, the cell boards can be hot-swapped to accommodate the growth.
"That means we can grow this box for a long time, York says, and adds that he expects five to seven years out of his Superdome.
Four stages of server consolidation
Each stage increases the complexity of the process but also improves the payback. Server consolidation can mean a variety of things to different people, and users considering launching a consolidation project would be wise to think through their goals. As a starting point, consider these four distinct phases for your server consolidation project, IDC says.
The easiest and most basic stage. During this stage, IT centralizes its various distributed application servers to one data centre by moving the physical boxes to a central location. Administration is eased, but not much is gained because the applications remain tied to a plethora of individual servers.
During this stage, IT combines like application servers -- say several Microsoft Exchange mail servers -- onto fewer or larger systems with the same application type or platform. This results in fewer servers overall, leading to lower maintenance and administrative costs.
During this stage, IT combines applications with different data formats onto a single platform. For example, it moves from a mix of database platforms to just Oracle. This not only reduces the number of application servers, but standardisation helps further streamline support and maintenance costs.
Provides the most bang for the buck. During this stage, IT consolidates servers supporting different application workloads onto fewer or larger systems.
Five ways to sell your server consolidation project
- Consolidate storage first to gain buy-in for the concept and then move on to application servers.
- Attack low-hanging fruit such as mail and print servers first and build on your success. costs.
- If you charge back, show savings that way.
- If you don’t charge back, then focus on detailing service-level improvements, staff/asset utilisation savings and business flexibility (all of which should exist at some level).
- Be patient and don’t consolidate all at once. Wait and consolidate when an upgrade is necessary anyway, and even then do it bit by bit.