Wondering how all the I/O requests by virtual machines are handled in Hyper-V? Hyper-V has a storage IO balancer which prevents one busy VM from starving another VM. The Performance Tuning Guidelines for Windows Server 2008 at http://www.microsoft.com/whdc/system/sysperf/Perf_tun_srv.mspx provides the following detail:
The virtualization stack balances storage I/O streams from different VMs so that each VM has similar I/O response times when the system’s I/O bandwidth is saturated. The following registry keys can be used to adjust the balancing algorithm, but the virtualization stack tries to fully use the I/O device’s throughput while providing reasonable balance. The first path should be used for storage scenarios, and the second path should be used for networking scenarios:
HKLM\System\CurrentControlSet\Services\StorVsp\<Key> = (REG_DWORD)
HKLM\System\CurrentControlSet\Services\VmSwitch\<Key> = (REG_DWORD)
Both storage and networking have three registry keys at the preceding StorVsp and VmSwitch paths, respectively. Each value is a DWORD and operates as follows. We do not recommend this advanced tuning option unless you have a specific reason to use it.
Note that these registry keys might be removed in future releases:
The balancer is enabled when set to a nonzero value and disabled when set to 0. The default is enabled for storage and disabled for networking. Enabling the balancing for networking can add significant CPU overhead in some scenarios.
This controls how much work, represented by a latency value, the balancer allows to be issued to the hardware before throttling to provide better balance. The default is 83 ms for storage and 2 ms for networking. Lowering this value can improve balance but will reduce some throughput. Lowering it too much significantly affects overall throughput. Storage systems with high throughput and high latencies can show added overall throughput with a higher value for this parameter.
This controls how much work the balancer issues from a VM before switching to another VM. This setting is primarily for storage where finely interleaving I/Os from different VMs can increase the number of disk seeks. The default is 8 percent for both storage and networking.
Here are some resources for your High Availability planning efforts for Hyper-V:
The RTM Vista SP1 Hyper-V management tools are available at:
Download the Update for Windows Vista (KB952627) package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=A46D0047-E383-4688-9449-83373226126A)
Download the Update for Windows Vista (KB952627) package now.
NOTE: Ensure that you have installed KB950050 on the Hyper-V server.
The UK's Register website recently posted an article on the security risks of 3rd party analytic code on your website. Specifically, they say Google Analytics — Yes, it is a security risk.
You have a policy in place about placing external client side scripting in a page you own, and you certainly prevent it from being placed on admin pages (as alleged in the article re the Obama website), RIGHT?
The Virtual Machine Migration Guide: How To Migrate from Virtual Server or Virtual PC to Hyper-V topic just published describes the steps for migrating your VMC or VPC VMs to Hyper-V.
...for all things Vista-related that take you away from supporting servers. Point them to the new Windows Vista Answers | Microsoft Answers site.
It is a new community driven web site for everyone who uses Windows Vista at home, and has questions about using or fixing problems with Vista. With community-driven forums, it is a place for Microsoft customers to discuss and ask questions about Vista.
Deva’s blog post New offers : Microsoft Virtualization details how you can get 2 free training courses on Hyper-V.
Issuing an out-of-band security update is a pretty rare occurrence. Must be important! Better go check now at: http://www.microsoft.com/technet/security/bulletin/MS08-078.mspx
No, seriously, go check now. It is important. Microsoft Security Bulletin MS08-078 is rated Critical for Internet Explorer 5.01, Internet Explorer 6, Internet Explorer 6 Service Pack 1, and Internet Explorer 7.
Here are some links to help you as you begin planning to deploy Hyper-V:
Hyper-V Release Notes
Hyper-V Planning and Deployment Guide
Hyper-V RAM Calculator Spreadsheet
Webcast: Virtualization Capabilities of Windows Server 2008 (Level 100)
Hyper-V: Hardware Considerations
Hyper-V Solution Accelerators: Infrastructure Planning and Design -Windows Server Virtualization
Dell Solutions Guides for Microsoft Hyper-V
Planning for Hyper-V Security
Security in a Virtual World Whitepaper
Hyper-V: Planning for Backup
MSDN & TechNet Powered by Hyper-V Whitepaper
You can check/manage these actions on the Virtual Machine settings (right click on the VM and select Settings: Management: Automatic Stop Action) as shown in this screenie:
Turn Off and Shutdown are pretty straightforward.
The Virtual Machine Management Service (VMMS) is registered to receive preshutdown notifications, a new feature in Windows Server 2008. When the VMMS receives the SERVICE_CONTROL_PRESHUTDOWN event, it fires the shutdown action on all of the active virtual machines. VMMS will wait for all active virtual machines to enter the specified shutdown state. The Service Control Manager (SCM) will wait indefinitely for the VMMS to shut down, as long as it is responsive. If the VMMS does not respond to subsequent SCM queries after 3 minutes, it will automatically be terminated.
Save State saves the current state of the virtual machine, and stops the virtual machine from running. Save State creates a temporary file is in the same location as the virtual machine configuration files with a .vsv extension that contains state information. When the virtual machine is restored from the saved state, it returns to the condition that it was in when its state was saved.
If you see problems in this area, go check how long your "Save State" operation takes on the suspect VM. Is it longer than 3 minutes? Do you have previous save state files (*.vsv) that need to be cleaned up?
The phrase is understood by many to mean "translators, traitors" (I like my punctuation better, makes it read more like the vocal curse I believe it was). In The Craft of Translation, the author puts it this way: ""Traduttore e traditore. The translator betrays."
I wrote about this first in the context of the nifty new features in Office 2007, but all product group UA folks struggle with this. The Microsoft Language Excellence team blog (yeah, we take it that seriously) post Windows Live terminology - what users told us has interesting insights. Check out the struggles over "smart phone", "emoticon" and "IM".
TechNet has launched a new troubleshooting page to help you in your times of need. Here’s a before-and-after screenie. How do you like the changes? Leave comments here and I will forward to the TN boffins….