POW #3 - Enable Windows Server Backup support for Hyper-V

October 8, 2008 at 9:41 AM2102

POW_Blue_SDid you try to backup Hyper-V Virtual Machines with Windows Server backup and received Event ID 521 error on Hyper-V host?


Backup started at '7.10.2008 23:21:14' failed as Volume Shadow copy operation failed for backup volumes with following error code '2155348129'. Please rerun backup once issue is resolved.


 Event ID 12302 error on guest computer?

Volume Shadow Copy Service error: An internal inconsistency was detected in trying to contact shadow copy service writers.  Please check to see that the Event Service and Volume Shadow Copy Service are operating properly.


Result of running vssadmin list writers command is empty?


Event ID 10102 error appears in Microsoft-Windows-Hyper-V-VMMS/Admin Event Log?

Failed to create the backup of virtual machine 'GUEST01'. (Virtual machine ID 0FBA408B-B269-4169-9278-EC650FEEBB1B)


Solution resides in the registry ;).

Fix VSS Event ID 12302 on Hyper-v guests

In order to get rid off Event ID 12302 on Virtual Machines you need to follow the following procedure:

  • Backup registry key:

  • Delete registry key Subscriptions.
  • Restart Virtual Machine (key will be regenerated after restart).
  • Verify that vssadmin list writers command returns valid list of writers.


 Enable Hyper-V VSS Writer with Windows Server Backup

In order to enable VSS backups of Hyper-V Virtual Machines, you need to add the following registry keys and String Value to enable Hyper-V VSS Writer with Windows Server Backup on Hyper-V host.


HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\
WindowsServerBackup\Application Support\{66841CD4-6DED-4F4B-8F17-FD23F8DDC3DE}

String Value:

Name: Application Identifier
Type: REG_SZ
Value: Hyper-V


Also check that Hotfix KB956697 (Windows Server 2008 Hyper-V VSS writer is not used during a backup job because of corrupted or invalid virtual machine configuration files.) is installed!

Microsoft Hyper-V Server 2008

I also have great news for all Hyper-V lovers. Microsoft released Microsoft Hyper-V Server 2008! The best thing about it is that it's FREE! Microsoft Hyper-V Server 2008 is a stripped version of Windows Server 2008 Core and contains only Windows Hypervisor, Windows Server driver model and virtualization components.

Microsoft® Hyper-V™ Server 2008 is a stand-alone product that provides a simplified, reliable, cost-effective and optimized virtualization solution enabling organizations to improve server utilization and reduce costs. It allows organizations to consolidate workloads onto a single physical server and is a good solution for organizations who want a basic and simplified virtualization solution for consolidating servers as well as for development and test environments. Low utilization infrastructure workloads, departmental applications and simple branch office workloads are also candidates to virtualize using Hyper-V Server 2008.


Hyper-V RC1 Released

May 26, 2008 at 12:58 PM2102

Microsoft Forefront Security for Exchange Server 2007 with SP1 Beta 2

September 1, 2007 at 12:28 AM2102

If you are brave enough you probably already tried Exchange Server 2007 Service Pack 1 Beta 2. ;-)

So if you want to install Forefront Security for Exchange don`t use RTM version of Forefront Security for Exchange. Microsoft provided special version for Exchange Server 2007 with Service Pack 1 Beta 2.

Forefront Security for Exchange Server SP1 Beta 2 integrates multiple scan engines from industry-leading security firms into a comprehensive, layered solution, helping protect your Microsoft Exchange Server messaging environments from viruses, worms, spam, and inappropriate content.

This new release provides support for Exchange Server 2007 SP1 and Windows Server 2008, as well as content filtering and manageability enhancements. These enhancements include:

  • Seamless support for organizations running IPv6.
  • Improved content filtering with installable keyword lists that can be used to eliminate email containing profanity in eleven supported languages.
  • Improved integration with Microsoft System Center Operations Manager through new management packs (available in Q4 2007) that allow administrators to proactively monitor the state of their Exchange 2007 protection.
  • Increased flexibility for scanning or blocking high compression zip files and RAR archives.

Note: Forefront Security for Exchange users who are running Exchange 2007 RTM and wish to upgrade to Exchange 2007 SP1 must first upgrade to Forefront Security for Exchange SP1.

You can download it here.

Posted in: Exchange | x64 | Longhorn | Microsoft | Forefront Security


Can Active Directory benefit from x64?

September 22, 2006 at 12:04 PM2102

We all know that Microsoft products such as Exchange Server 2007, SQL 2005 x64 can really benefit from x64 platform. But what about Active Directory? Similar to the limitations of Exchange Server 2003, Active Directory suffers from the 2GB virtual memory limit of 32bit operating systems. That`s not a problem for small AD deployments but it can be a real issue for large deployments with a LOT of objects. With large number of object it gets difficult to cache the Active Directory database and authentication requests and queries leads to excessive paging and a slowdown in performance.

So if you are planning or working with a large Active Directory deployments than go for x64 platform. Especially now when prices for 32 and 64bit platform are almost the same. [Y]

Let me quickly try to explain about 2GB memory limit in 32bit operating systems.  You probably all heard about the Windows 4GB memory limit. When talking about performance tuning and server sizing, people are quick to mention the fact that that an application on an 32bit Windows system can only access 4GB of memory.

What does that really means?

A 32 bit processor uses 32 bits to refer to the location of each byte of memory. 2^32 = 4.2 billion. That means a memory address that`s 32 bits long can only refer to 4.2 billion unique locations in memory (that`s 4GB of memory). (Source: Wikipedia)

In the 32bit Windows each application has its own »virtual« 4GB memory space. This 4GB memory space is distributed into two parts, with 2GB dedicated for kernel and 2GB for application usage. Each application has its own 2GB, but all have to share the same 2GB kernel space. Using the /3GB boot.ini switch is even worse in some cases (Terminal Server for example). This switch changes the amount of memory for application and kernel environment. It gives 3GB of memory for application environment and »only« 1GB of memory for kernel. But if you are using /3GB boot.ini switch for SQL Servers you can gain performance since it`s a memory-intensive application (and not kernel).

There is a difference when systems are booted using /PAE switch. Physical Address Extension (PAE) is an Intel provided memory address extension that enables support of up to 64GB of physical memory for application. PAE allows the most recent IA-32 processors to expand the number of bits that can be used to address physical memory from 32bits to 36bits trough support in the host operating system for applications using Address Windowing Extension (AWE) application programming interface (API). AWE enables programs to reserve physical memory as non-paged memory and then to dynamically map portions of the non-paged memory to the program`s working set of memory. This process enables memory-intensive programs, such as I already mentioned before (SQL – databases), to reserve large amounts of physical for data without having to be paged in and out of a paging file for usage. Instead the data is swapped in and out of the working set and reserved memory is in excess of the 4GB range.  Additionally, the range of memory in excess of 4GB is exposed to the memory manager and the AWE functions by PAE. Without PAE, AWE cannot reserve memory in excess of 4GB.

Posted in: Windows | Active Directory | x64