Ravi Sankar: Virtualization

Hyper-V 1.0 @ RTM - How good is it?

Mon, 30 Jun 2008 02:51:28 GMT

If you want to know how reliable and scalable Hyper-V is, here is a quick list of Hyper-V statistics.

40% of www.microsoft.com runs on Hyper-V
MSDN and TechNet web sites are completely running on Hyper-V
Nearly 150 customers of Microsoft are using it in production as part of early adoption program
Test figures have shown that I/O performance under Hyper-V is 90-97% of native performance
Microsoft partner QLogic has achieved a throughput of 180,000 I/O per second for a storage device through Hyper-V

Of course there is more. This URL can give you more detailed information

Technorati Tags: Hyper-V,Virtualization,performance

Hyper-V is not based on Xen source code

Fri, 04 Jan 2008 10:00:35 GMT

There are few articles taking prowl in the Internet stating that Microsoft's Hyper-V is based on Xen's source code. This is not true and colleague has blogged about it here

Technorati Tags: Hyper-V,Virtualization

VMRC Plus is available now

Tue, 03 Jul 2007 08:24:09 GMT

VMRC Plus is a very cool and powerful tool for managing virtual machines running in a Microsoft Virtual Server environment. The following are some of the most important benefits of using VMRC Plus

IIS and VMRC are not required
Far better interface than IE based console for administration
Manage multiple guest and host machines from the same console
Supported on Microsoft Virtual Server 2005 R2 SP1
It displays the disk, network, memory and CPU usage statistics nicely
It FREE too!!!

You can download this tool from here.

Technorati Tags: Virtual Server, VMRC plus

NIC speed in a virtual machine running on Microsoft Virtual Server

Tue, 19 Jun 2007 11:44:25 GMT

The virtual machines running in a Microsoft Virtual Server instance shows that the virtual NIC operates @ 100Mbps even when the physical adapter is 1Gbps. But this indication is not correct. The virtual NIC is actually operating at 1Gbps.

Technorati tags: virtual server

I prefer Virtual Server

Thu, 24 May 2007 16:02:28 GMT

Even for demo purpose I prefer Virtual Server than Virtual PC because of performance reasons. While running multiple virtual machines, virtual server gives better performance due to its multithreading capabilities.

Technorati tags: Virtualization, virtual server, virtual pc

No VM Additions but Integration Components

Sat, 28 Apr 2007 11:17:33 GMT

In Microsoft Virtual Server and Microsoft Virtual PC we install "VM Additions" to improve the performance of the virtual machines and to enable time synchronization with the host machine. But VM Additions won't be there in Windows Server Virtualization (WSV). Instead, WSV is going to have something called "Integration Components". One of the features included in the Integration Components is the Virtualization Service Client (VSC) which I described in one of my earlier blog posts. Other features include time synchronization and heartbeat functionality.

What is VSP/VSC/VMBus in Windows Server Virtualization?

Sat, 28 Apr 2007 07:55:44 GMT

Virtualization Service provider (VSP): This is the component of WSV which runs in the parent partition and directly communicates with the hardware drivers. VSP makes sure that the other virtual machines (child partitions) running in the same host can access the hardware successfully. It also ensures that the hardware access and sharing by multiple virtual machines is secure. For example VSP is responsible for sharing a common storage device across multiple virtual machines.

Virtualization Service Client (VSC): VSC runs in the child partitions and presents the virtual device to each child partition. For a given VSC there would be a corresponding VSP in the parent partition. In other words VSP and VSC exist as pairs. For example there would be a VSP/VSC pair for storage device.

VMBus: This is a point to point in memory bus and is used by VSP and VSC to communicate with each other

Drivers and Hyper-V

Mon, 23 Apr 2007 15:03:48 GMT

Often questions are asked about where the hardware drivers are loaded in Hyper-V. Some virtualization vendors load drivers in their hypervisor. But for improved security and reliability Windows do not load the divers onto Windows Hypervisor. Instead drivers are loaded onto the parent partition. These drivers are regular Windows drivers and do not require any customization for virtualization.

Technorati tags: Hyper-V, Virtualization

New Operating System Support in Microsoft Virtual Server

Thu, 12 Apr 2007 11:31:03 GMT

Microsoft is proving again that they are committed to interoperability in their products and solutions. The virtual server team will soon release the latest update (SP1) of their product, Virtual Server 2005 R2 . This release would officially support two new operating systems – Suse Linux 10 and Solaris 10 - as guests. Now Solaris would run as a window on my desktop. That's so cool, isn't it?

Technorati tags: Virtual Server, Service Pack

Hardware assisted virtualization and Toshiba Tecra M5

Sat, 07 Apr 2007 09:01:31 GMT

One of the reasons why I got so excited about my Toshiba Tecra M5 was that it supports hardware assisted virtualization. Virtual PC 2007 (VPC 2007) can take advantage of this feature and provide improved performance for virtual machines. So I started using VPC 2007 ever since the beta was launched. But I always found that the "Enable hardware-assisted virtualization" option is greyed out. Initially I thought that this could be a problem with the beta version of VPC 2007 and I just ignored it. Later when the full version got released I checked the same setting to see that it was still greyed out. Then I started suspecting the BIOS settings and found out that virtualization was not enabled thereL. As soon as I found this out, I enabled the same in the BIOS and went to check whether VPC 2007 was recognising it or not. But the option "Enable hardware-assisted virtualization" was still greyed out. I did not know what to do next. Finally I decided to ask few of my colleagues to see whether they were facing the same issue or not. Within minutes I got e-mail replies saying that this could be a BIOS problem. And finally I got suggested to upgrade the BIOS to version 3.20. I got thrilled and was damn sure that this solution would work. It was late in the night. But I couldn't resist. I started downloading the latest BIOS update (3.6MB) from Toshiba's web site using one of the slowest internet connections (Tata Indicom data card) available in the world today. I think it took half an hour for me to get the file downloaded on to my machine. I did not wait for even half a second to start the installation. But here comes the saddest moment in the entire story. My OS was 64 bit and the setup was supported only in 32 bit OSLLL. So there was no way I could upgrade my BIOS that night itself. I went to the bed in great despair. Today I am here in office to reinstall my laptop with a 32 bit Vista OS. But I finally I managed to upgrade my BIOS to version 3.20 and now I am in a state of nirvana because I can see the option "hardware assisted virtualization" enabled in VPC 2007.

Technorati tags: hardware virtualization, tecra m5

Hot Add/Remove of Hardware in Hyper-V

Sat, 07 Apr 2007 05:02:27 GMT

Processor: Hyper-V supports hot addition of processors to virtual machines provided the guest OS supports the same. Guest OS supporting this option are Windows server Longhorn Enterprise and Datacenter editions. Hot removal of processor is not supported. But administrators can use the dynamic resource allocation feature to achieve effectively the same goal.

Memory: Hyper-V allows hot addition of physical memory resources to virtual machines provided the guest OS supports the same. The guest operating systems supporting this configuration are Windows Server 2003/Longhorn Enterprise & Datacenter editions. Hot removal of memory is not supported. But administrators can use the dynamic resource allocation feature to achieve effectively the same goal.

Storage: Hyper-V lets virtual SCSI devices to be added or removed while the virtual machine is running provided the guest OS supports the same. The guest operating systems supporting this configuration are Windows Server 2003/Longhorn Enterprise & Datacenter editions.

Network Adapter: In Hyper-V it is possible to hot add/remove virtual network adapters provided the guest OS supports this feature. The following guest operating systems support this feature
• Windows 2000 server/advanced server
• Windows server 2003 Enterprise/Datacenter editions
• Windows server Longhorn Enterprise/Datacener editions

Also Microsoft is jointly working with XenSource to make many of these features available in Linux OS.

Technorati tags: hot add, Hyper-V

New Features in Microsoft Virtual Server 2005 R2 SP1

Fri, 06 Apr 2007 07:14:34 GMT

These days I have been writing a lot about Windows Server Virtualization (WSV). But now I realize that I forgot to mention few important things about the Microsoft Virtual Server R2. The service pack 1 of Microsoft Virtual Server R2 is going to be released soon. You can download the beta 2 from here. Some of the major enhancements made in this release are

Support for hardware assisted virtualization: AMD virtualization (AMD – V) and Intel virtualization technology (IVT) are now supported
Support for volume shadow service. This allows the snapshot backup of all virtual machines running in a physical host without any downtime.
Offline mounting of VHD files. This would help administrators to run scripts against the virtual machine hard disk files while the virtual machines are turned off. For example virus scanning can be done when a virtual machine is turned off.
Windows Vista will be supported as a guest operating system
Physical memory support up to 256 GB as against 64GB today
Virtually unlimited number of virtual machines per 64 bit physical host. But this number is practically limited by the amount of hardware resources available.
Technorati Tags: Virtual server 2005 R2 SP1, Offline VHD, Intel VT, AMD virtulization

Memory reserve feature in Windows Server Virtualization (WSV)

Tue, 20 Mar 2007 15:42:32 GMT

Let me explain this concept with the help of an example. Assume that there is a virtual machine with 1GB of allocated memory. If the memory reserve (always a percentage value) for this machine is 75% it is guaranteed to have 750MB of physical memory (RAM). I.e. while this machine is running, no paging happens for the first 750MB required by the machine. The remaining memory (250MB max as the allocation is 1GB) can be either physical memory (if it is available) or page file.

This feature is useful only in software test/development environments where the availability of RAM is a major constraint but performance is not. For maximum performance 100% memory reserve is recommended. The default configuration of any virtual machine is 100% memory reserve. Today in Microsoft Virtual Server 2005 the memory reserve is always 100% and is not configurable.

Page sharing in Windows Server virtualization (WSV)

Thu, 15 Mar 2007 15:57:12 GMT

WSV allows sharing of identical pages between virtual machines running on the same hardware. That is if multiple operating systems or applications are using identical pages only one instance of the page is required. The same page would be used across operating systems or applications. The net effect is increased virtual machine density per physical machine. So a good design practice is to host maximum number of identical operating systems in a physical box.

I know that the next question would be about the security of such a system. I have an answer too. This feature can be turned on or off as per your security requirements. More than that this setting is configurable on a per virtual machine.

Another area of concern would be performance. Yes, you can expect some amount of degradation in performance.

What’s new in Windows Server Virtualization (WSV)?

Sat, 10 Mar 2007 06:39:25 GMT

Ø No VMRC. RDP will be used for remote connection to virtual machines. But BIOS would still be accessible

Ø X64 guest operating systems would be supported

Ø Multi core processor support within virtual machines (VM)

Ø More than 32 GB of RAM per VM

Ø VLAN support

Ø Number of VMs per physical machine depends on the hardware capacity

Minimum system requirements for Windows Server Virtualization (WSV)

Sat, 10 Mar 2007 06:33:24 GMT

Ø Windows server code named Longhorn x64 edition

Ø Hardware with Intel-VT or AMD-V technology. Majority of hardware available today has this feature. This feature is available in laptops also. But make sure that hardware assisted virtualization is turned on at the BIOS level

Ø Hardware with Data Execution Protection (DEP) feature. In AMD and Intel based servers it is known as AMD NX bit (no execute bit) and Intel XD bit (execute disable bit) respectively. This feature should also be turned on at the BIOS level. This feature basically prevents buffer over flow type attacks by not allowing code-execution from memory locations reserved as “data only”. (Yes, there are smart ways to fool this technology as well!)

Cool demo on Windows Server Virtualization (WSV)

Sat, 10 Mar 2007 06:15:31 GMT

http://soapbox.msn.com/video.aspx?vid=5119240c-6579-4827-8338-7f5539930402

What is Hyper-V?

Sat, 10 Mar 2007 06:12:50 GMT

Hyper-V is the hardware assisted virtualization and is going to be part of the next version of Windows server code named as Longhorn. Hyper-V allows multiple virtual machines to run on a single piece of server hardware. This helps IT managers and system administrators to

a) Reduce the number of servers they manage in a data centre

b) Reduce the overall power consumption

c) Reduce the total rack space required

And in some cases you can save the license fee too!

How dynamic media access control addresses are assigned to virtual network adaptors in Virtual Server 2005

Sat, 07 Oct 2006 13:47:56 GMT

One of the interesting questions came up during my recent sessions on Virtual Server was about ensuring uniqueness of MAC addresses generated by Microsoft Virtual Server (MVS)

This is how it works

Linux Guest Support for Virtual Server 2005 R2

Tue, 22 Aug 2006 14:11:18 GMT

The following Linux operating systems have been tested and are on the list of supported guests for Virtual Server 2005 R2:

• Enterprise distributions:

• Red Hat Enterprise Linux 2.1 (update 6)

• Red Hat Enterprise Linux 3.0 (update 6)

• Red Hat Enterprise Linux 4.0

• SuSE Linux Enterprise Server 9.0

• Red Hat Linux 7.3

• Red Hat Linux 9.0

• SuSE Linux 9.2

• SuSE Linux 9.3

• SuSE Linux 10.0

The Virtual Machine Additions for Linux are available through Microsoft Connect.

For more details http://www.microsoft.com/windowsserversystem/virtualserver/evaluation/linuxguestsupport/default.mspx