Comments on: vSphere Memory Hot Add/CPU Hot Plug

By: VCAP-DCA Objective 6.2 – Troubleshoot CPU and Memory Performance

VCAP-DCA Objective 6.2 – Troubleshoot CPU and Memory Performance — Sun, 01 Aug 2010 13:53:35 +0000

[...] couple of good blogs by David Davis and Jason Boche outline what and how to use Hot-Add/Hot-Plug. The ability to use this without having to reboot the [...]

By: vSphere 4.1: Multicore Virtual CPUs » boche.net – VMware Virtualization Evangelist

Sun, 25 Jul 2010 18:45:24 +0000

[...] you configure multicore virtual CPUs for a virtual machine, CPU hot Add/Remove is disabled (previously called CPU hot [...]

By: vSphere Hot Memory Add | vmexplorer

vSphere Hot Memory Add | vmexplorer — Fri, 23 Jul 2010 05:00:27 +0000

[...] http://www.boche.net/blog/index.php/2009/05/10/vsphere-memory-hot-add-cpu-hot-plug/ [...]

By: VMWare – Linux gäst, hur gör man för bästa prestanda? « Håkan & Marie's upplevelsesida

Thu, 08 Apr 2010 14:01:06 +0000

[...] Här kan man läsa mer utförligt om testerna för Windows platformar http://www.boche.net/blog/index.php/2009/05/10/vsphere-memory-hot-add-cpu-hot-plug/ [...]

By: VCP 410 Exam Course Notes « server and storage

VCP 410 Exam Course Notes « server and storage — Tue, 23 Feb 2010 05:50:21 +0000

[...] http://www.boche.net/blog/index.php/2009/05/10/vsphere-memory-hot-add-cpu-hot-plug/ [...]

By: Ernst Cozijnsen

Ernst Cozijnsen — Wed, 13 Jan 2010 10:23:00 +0000

The article is looking very good i must say.

The only thing that is bothering me is the wrong info about X86 and X64

X86 is saying something abou the Intell architecture and doesn’t say anything about 32 or 64 bit. X86 cis and will remain the architecture layout.

IA64 was the 1st new architecture of Intell which had a BIT comment in the name: Itanium Archtecture 64 (bit)

By: VMware Hot-Add Memory/CPU Support – Gestalt IT

VMware Hot-Add Memory/CPU Support – Gestalt IT — Mon, 14 Dec 2009 15:01:42 +0000

[...] focused on Microsoft: VMware Guest/Host OS Compatibility Guide There is Jason Boche’s great article which he researched and tested himself, And Daniel Eason’s summary on [...]

By: Darrell Hoberer

Darrell Hoberer — Sun, 30 Aug 2009 18:43:56 +0000

Thanks for the good article. I appreciate your insights!

By: RTFM Education » Blog Archive » What I learned today… Hotadd & VMware PowerPath

Wed, 22 Jul 2009 18:28:16 +0000

[...] it has come to my attention via David Davis and Jason Boche (behind Jason’s name is link that takes you to his testing on hot-add) that hot-add might not [...]

By: jason

jason — Tue, 02 Jun 2009 04:46:56 +0000

Great comments. I think it’s going to be quite a while before change management is ready for hot add cpu or memory. I know VMotion was a new concept for changement and many people like to make that comparison, but with hot add/remove, we’re making major changes to the guest OS. This really takes things to a whole new level.

By: Jimmy

Jimmy — Tue, 02 Jun 2009 04:18:46 +0000

I think it may be different for each application.
I remember seeing a demo of CPU Hot plugging for Windows prior to 2008′s release, where an actual command had to be issued to inform Windows to start sharing the load across the newly added CPU.

SQL Server:
See here: http://technet.microsoft.com/en-us/library/bb964703.aspx

For some info about hot-adding CPUs in Windows.

“*SQL Server does not automatically start to use CPUs after they are added. This prevents SQL Server from using CPUs that might be added for some other purpose. After adding CPUs, execute the RECONFIGURE statement, so that SQL Server will recognize the new CPUs as available resources.”

So basically, I think reboot is a sure thing, or restart all your applications, but some apps should let you change their affinity live.

Even if that’s just SQL and Exchange, well, those are pretty common apps you see on Windows servers.

By: jason

jason — Fri, 29 May 2009 05:36:05 +0000

cdarn: Yep, hot remove of virtual disk is in vSphere.

By: cdarn

cdarn — Fri, 29 May 2009 05:22:50 +0000

Jason,

You don’t happen to see a hot remove for virtual disks within a running VM in vsphere do you? Since it’s not in the marketing sheet I doubt it’s there but I thought I would ask.

By: netmon1

netmon1 — Thu, 28 May 2009 18:17:06 +0000

Thanks for the post, I like the amount of testing you did across multiple OS versions/architectures. Since Windows Server Enterprise Edition allows you do 4 virtual installations adding memory on the fly could be useful. However I would think in most situations (at least in small/medium businesses) that you would have already configured the guest for the appropriate amount of memory.

By: Christopher

Christopher — Tue, 12 May 2009 14:22:50 +0000

Clarification:

Windows Server 2003 SP1 Enterprise Edition and Datacenter Edition support hot add of memory on x86-based, x64-based, and Itanium-based systems.

Windows Server 2008 supports hot add of processors, memory, and I/O host bridges plus hot replace of processors and memory on x64-based and Itanium-based systems.

Note: Although Windows Server 2008 does not support hot remove, Microsoft is considering including support for hot remove in a future version of Windows Server.

Source: Microsoft Windows Server 2008 Dynamic Hardware Partitioning White Paper

Long Version: http://download.microsoft.com/download/8/2/f/82fa3808-7168-46f1-a07b-f1a7c9cb4e85/WS08%20Dynamic%20Hardware%20Partitioning%20White%20Paper%20Final.doc

Short Version: http://tinyurl.com/ptrzmn