Q: How much power does an idle server consume?

A: Way more than a powered-off server.

VMware vSphere saves energy — and money — in your datacenter by powering off unused hosts during off-peak periods.  Take a look at this new technical paper on VMware DPM that covers the technology in-depth.

Despite competitor claims, this powerful capability is unique to VMware vSphere.

Imitation: The highest form of flattery

Red Hat Enterprise Virtualization has a seemingly-similar feature called Power Saver that also consolidates virtual machines onto fewer hosts.  However, the RHEV solution stops there — hypervisor hosts simply sit idle with no running VMs; they are not powered off.  No word yet on what the moon and stars in this diagram have to do with an idle host:

Red Hat claims that an idle host requires just 10-15% of the power required for a host with running VMs.  That sounds very generous if you ask me.  Frankly, from the looks of my HP C7000 BladeSystem Onboard Administrator power summaries, it seems quite false.

Update: Bob Plankers actually measured the power consumption of a Dell server in a few different scenarios and found that idle systems still draw significant amps.

Red Hat claims their new virtualization product is “best in class.”  Really?  Which class?

Related posts:

1. RHEV Wrap-Up
2. What is Red Hat Enterprise Virtualization?
3. These are not the files you are looking for
4. Multiple hypervisors? What about multiple SANs?

If you have considered using VMware DPM  in your datacenter but have hesitated due to lack of official server hardware manufacturer support statements, today’s news should provide the assurance you need to begin investigating how much power you can save.

By the way, it looks like Chris Wolf was on to something when he recently wrote:

DPM can result in substantial power and cooling cost reduction by shutting down unneeded servers in a given ESX cluster, and then turning them back on once they’re needed again. Once the IHVs step up and do their part, I expect some Burton Group clients to begin implementing DPM for some of their workloads.

Have you been using VMware DRS or were you holding out for formal support statements from your vendors?

Meet the Engineer Video

In this recent video you can see one of the primary VMware engineers behind DPM.

If you are reading this post via RSS and do not see the video, please click over to the VCritical blog for the full experience.

Related posts:

1. Awesome performance through VMware DRS
2. Idle RHEV Hypervisors save power?
3. vSphere Console Stays Connected During VMotion
4. VMware vCenter Server 4.0 installation video