My Blog has a copy, Beware of counterfeits : TAKE 2

Today I realized another blog stealing my precious content :) This time it's under blogger.com domain.

http://microsoft-systemengineer.blogspot.com/

I even see this guy's blog posts have higher page ranking in Google for some of my articles. How fair !

Hyper-V Best Practices Analyzer

Microsoft released a best practices analyzer for Hyper-V on Windows 2008 R2 only which can be found on the following link :
http://support.microsoft.com/kb/977238/en-us

Hotfix : Windows 2008 R2 + Hyper-V + Intel Nehalem = Blue Screen

If you have Windows 2008 R2 + Hyper-V running on Nehalem CPU(Intel Xeon 5500 or Core-i) and getting blue screen messages with 0x00000101 - CLOCK_WATCHDOG_TIMEOUT stop code then you will definetly need to check the KB below :

http://support.microsoft.com/default.aspx/kb/975530

Before applying the Hotfix to your platform take into account the warning from MS :

Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

Windows 2008 R2 Migration Utilities for Hyper-V

Windows 2008 R2 Migration utilities has been updated with support for Hyper-V. Now it's possible to migrate your Hyper-V setup including VMs,Virtual Switches,VMQ,Chimney Settings etc.. to a Windows 2008 R2 host. The support is from :

Windows 2008 x64 Full Only
Windows 2008 R2 x64 Core or Full Edition to :

Windows 2008 R2 x64 Core or Full Editions. Also from documentation the scenarios that are not supported are  :

• The saved state of a virtual machine under one of the following conditions:
  
  • When moving from Hyper-V in Windows Server 2008 to Hyper-V in Windows Server 2008 R2.
  • When moving between physical computers that have different processor steppings or vendors—for example, migrating from a computer with an Intel processor to a computer with an AMD processor.
• Virtual machine configuration under one of the following conditions:
  
  • When the number of virtual processors configured for the virtual machine is more than the number of logical processors on the destination server.
  • When the memory configured for a virtual machine is greater than the available memory on the destination server.
• Consolidation of physical servers to virtual machines, or consolidation of multiple instances of Hyper-V to one instance.

http://www.microsoft.com/downloads/details.aspx?FamilyID=5c1ec14a-e9d7-46ea-9c6e-73d6bc4219b4

Documentation:

http://technet.microsoft.com/en-us/library/ee849855(WS.10).aspx

F5 System Engineer LTM Certified

Yesterday I passed the second and final exam in the F5 System Engineering track F50-522. Without breaking NDA lets go into an overview of the exam :
- As I mentioned in LTM Essentials F50-521 exam, the questions are mostly based on theory. So you need to know hot things works instead of how things are done. Having more then 3 years of hands on with those devices, I really had hard time on some of the questions :)
- Majority of the questions requires you to have a deep understanding of Virtual Server types (network,transparent,forwarding), SNAT/NAT concepts like automap and how source and destination IP@ changes from client to member node.
- Master the iRules. Know the context for each method. Know how context changes the behavior of local_address/remote_address etc..
- Master TCL functions like findstr,starts_with,ends_with etc..
- Know variety of logging options like alertd,syslog-ng and snmpd
- And for sure you need to have a good understanding of how HTTP works. Cookies, Keep-alive messages and their interaction with One-Connect profiles, XForward headers etc..

Hyper-V Live Migration Network Configuration Guide from Microsoft

Microsoft just released a network configuration guide for Windows 2008 R2 Hyper-V Live Migration feature. It's short but useful article at least for design perspective.

This guide describes how to configure your network to use the live migration feature of Hyper-V™. It provides a detailed list of the networking configuration requirements for optimal performance and reliability, as well as recommendations for scenarios that do not meet these requirements.

 http://technet.microsoft.com/en-us/library/ff428137(WS.10).aspx

Microsoft recommends Increasing VMBus buffer size on Hyper-V for better network throughput

I read an article on Windows Server Performance team blog. Basically it's recommending increasing the VmBus buffer size from 1MB to 2MB to get a better network throughput and a less chance of packet loss for VMGuest NICs on Hyper-V. 

"Your workloads and networking traffic may not need increased buffers; however, these days, 4Mb of RAM isn’t a tremendous amount of memory to invest as an insurance policy against packet loss. Now, if only I could increase a few buffers and alleviate congestion on my daily commute!"

http://blogs.technet.com/winserverperformance/archive/2010/02/02/increase-vmbus-buffer-sizes-to-increase-network-throughput-to-guest-vms.aspx

In order to make the change (source above) :
On the Guest OS , In the Network Adapter Properties dialog, select the Details tab. Select Driver Key in the Property pull-down menu as shown in figure 1 (click the images to see a version that's actually readable):

 

Record the GUID\index found in the Value box, as shown in figure 1, above. Open regedit and navigate to:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{GUID}\{index} as shown in figure 2:

 

Right click the index number and create two new DWORD values, entitled ReceiveBufferSize and SendBufferSize (see figure 3). These values measure the memory allocated to buffers in 1Kb units. So, 0x400 equates to 1,024Kb buffer space (the default, 640 buffers). In this example, we’ve doubled the buffer size to 0x800, or 2,048Kb of memory, as shown in figure 3: