CPU for service console

[pranags]

I have a doubt whether the service console is always bound to 1 physical CPU or 1 logical CPU?

Can I set the CPU affinity for service console like I do for Virtual machines.?

Thanks,

Prasad.

[azn2kew]

Service Console is not a Host OS

The service console is used as a bootstrap for the VMkernal but once the VMkernal has started it has full control of all hardware assigned to it. The service console OS (Linux) has its resources controlled by the VMkernal just like a VM.

Here is a Direct quote from an ESX PDF.

"The purpose of the service console is to boot the physical server machines and administer

virtual machines. After the machine boots into the service console, the VMkernel is loaded and

takes over the machine. The service console supports devices that are not performance critical,

such as the mouse, keyboard, screen, floppy drives, CD-ROM, COM ports, and parallel ports. The

service console also runs applications that implement support, management and

administration functions. The ESX Server resource manager schedules the service console to

run, as needed. The service console is special in that it always runs on physical CPU 0. Virtual

machines can also run on physical CPU 0, but the service console cannot move to other physical

CPUs." </dt>If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!

Regards,

Stefan Nguyen

iGeek Systems LLC.

VMware, Citrix, Microsoft Consultant

[IB_IT]

The SC layer is much like a virtual machine in that it is separate from the vmkernel layer...but I do not think (or I do not know of a way) you can set CPU affinity in SC.

[RParker]

Looking at the post by akn2kew, the SC is pinned to CPU 0 anyway, so there you go. It's limited to 2.5Ghz of speed.

[Texiwill]

Hello,

The SC is nothing more than a specialized Management Appliance. The boot process is that the vmkernel boots, creates a VM, loads the SC Kernel and boots the SC. Once the SC is booted, it communicates with the vmkernel to do some book keeping and late startup of some but not all drivers.

But yes, the SC VM is pinned to CPU 0.

Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education. As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

[pranags]

Thanks for the details. My question now is for a CPU having multiple cores, I wanted to know wether the service console is bound to just 1 core or it can run on any of the cores on that CPU.?

Could you also let me know of any vmware documents indicating service console CPU speed limited to 2.5 GHz.

Thanks,

Prasad.

[mcowger]

Its always bound to the first core of CPU0.

Its not limited to 2.5GHz, its limited to the clock speed of your cores, whatever that may be.

--Matt

[azn2kew]

I'm just curious, what are you trying to accomplish by knowing SC CPU location and usuage? If you need speed, first you need to increase your SC to 800MB RAM so that can takes care of your SC performance issue but nothing else I know of.

If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!

Regards,

Stefan Nguyen

iGeek Systems LLC.

VMware, Citrix, Microsoft Consultant

[RParker]

&gt; Its not limited to 2.5GHz, its limited to the clock speed of your cores, whatever that may be.

Its limited to 1 core speed (in my case) 2327 Mhz. It has limited speed. It's even listed there under configuration - &gt; system resource allocation. The SC is capped.

[Texiwill]

Hello,

The SC is pinned to CPU0 Core0 and capped to 2.5Ghz, It also has caps on its write through speeds to the VMFS. In essences the SC runs on CPU0 Core 0, but so does the vmkernel, remember that the vmkernel is a different beast that all the VMs talk to including the SC. I generally ignore this Core when doing calculations on how many VMs the system will hold. Can this core run other VMs? Yes, if you overcommit the system quite a bit, but those VMs will always play second fiddle to the vmkernel and SC combination.

Your SC should do as little processing as possible to keep its CPU utilization low. If it is high then it will impact the vmkernel which will impact the rest of the VMs.

Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education. As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

[devzero]

It also has caps on its write through speeds to the VMFS.

is that tuneable somewhere?

[RParker]

is that tuneable somewhere?

No. The SC isn't meant to do ANYTHING except run diagnostics to send to VM Ware and to do basic tasks like fix network issues, basic ESX host maintenance. That's all it's really for. It should not be used for a VM Replacement or to run agents in (even though some can). That's why it's capped.

You really can't 'tune' it. It's not meant for users, it's meant for VM Ware to troubleshoot ESX host. In fact in the next release of ESX (vSphere) there is no console. Everything will be remote command line.

[devzero]

huh?

could you please point to some docs or some vmware employee`s statement to underline what you`re telling here ?

[RParker]

could you please point to some docs or some vmware employee`s statement to underline what you`re telling here ?

Scroll up. RE-read Texiwill's post.

[devzero]

sorry - but where does he tell that the SC is isn`t meant to do ANYTHING besides....?

where does he (or others) tell, that ESX4 has no service console ?

furthermore, i`m not sure if he is a vmware employee - he is a forum moderator, but i don´t see a vmware icon with his profile....