GreenITStrategy.com

First up - Happy New Year! :) I had a relaxing time (apart from the stupid oven cracking it halfway through the roast on Xmas day) and, when the mood struck me, I spent time updating my website with new features and content.

Back into the swing, in early December the Windows Server Performance <guys/girls/whatever> released a great new whitepaper with quite a lot of detail around optimisation of servers, as well as publishing their test results.

Some of the best practices covered include:

• Shut down idle machines during off-peak times.
• Opt for 2.5-inch instead of 3.5-inch disk drives.
• Use low-revolutions-per-minute (RPM) disk drives where it is possible.
• Select power-efficient processors and memory.
• Install variable-speed fans and efficient power supplies in servers to reduce waste.
• Use remote-controlled power strips to completely eliminate electricity flow to "powered-off" servers.
• Ensure that Windows Server 2008 is configured to use the Balanced power policy.
• Tune processor power management parameters to increase efficiency by up to 10 percent.
• Consolidate workloads or combine server roles on idle and underutilized servers where it is possible.
• Turn off hardware-based power management
• Deploy the latest service packs and Windows Server releases.
• Remove or shut down unnecessary roles, applications, and devices.

The 'shut down idle machines during off-peak times' section references a good article by Dave Ohara which provides some more practical suggestions for how you actually achieve this.  However I do question the viability of turning off servers when they are not in use in **some** environments:

• Issue number 1: I know that some of my customers have trouble even identifying what applications are running on certain servers and what the subsequent business impact would be if there were turned off.  This sounds highly unlikely and slightly dark ages to some IT departments but I know from talking to others this is the case, especially on older hardware and OS' that 'just keep running in the corner'.  This is not to say I condone not knowing what servers do - just pointing out that turning off idle machines is a more complex analysis process upfront for some.
• Issue number 2: in regards to actually identifying some servers that don't need to be running at certain times of the day - I think this may be a nirvana situation in some less-than-leading-edge environments.  Probably the 'easier-target' scenario I could see this working in is where you have a bank of servers, which Dave rightly points out - something like a Citrix farm in which each server may generally be configured identically and en masse (which would provide capability even at reduced performance until a new server(s) came up from being turned off, if that was necessary).

The whitepaper starts to get really meaty towards the middle of the document, covering some great detail on areas such as efficiency analysis, ACPI (C-States, P-States, T-States), interrupts, timers and test results for removing components to measure their power draw.  A few good points:

• Even when powered off, the test server consumed 27 watts - you might often hear a similar story along the lines of 'unplug your mobile phone because it draws power even when turned off at the point but is still plugged in'.
• In the tests Memory consumed 54% of the total system power.  Newer RAM consumes less power due to modern energy efficiencies.
• Using 2.5" disks instead of 3.5" disks doesn't impact performance but does consume 50% less power.

Anyway before I give away the storyline, I'll let you go read the paper yourself:  http://www.microsoft.com/whdc/system/pnppwr/powermgmt/Svr_Pwr_ITAdmin.mspx

Also check out a related blog post by the team who wrote this whitepaper, focusing on tuning power processor performance: http://blogs.technet.com/winserverperformance/.