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.


POW #2 - Upgrading legacy filters

October 2, 2008 at 2:30 PM2102

POW_BlueI just migrated from Microsoft Exchange Server 2000/2003 to Microsoft Exchange Server 2007. What is this thing with upgrading E-Mail Address Policies, Address Lists,...?

I receive this question quite often. So let's try to answer.

Exchange Server 2007 uses a new filter syntax (OPATH) to replace the traditional LDAP filters. So what is OPATH? OPATH is filtering syntax used by PowerShell, and is therefore also used by Exchange Server 2007. Remember that the whole Exchange Server 2007 administration is done via PowerShell! OPATH replaces complicated syntax used by LDAP filters in Exchange Server 2000/2003.

Which (default) filters do we need to upgrade?

  • Email Address Policies
  • Global Address Lists
  • Address Lists

Let's start with Email Address Policies. Here is LDAP Recipient Filter that comes with Exchange Server 2000/20003:



As you can see only LDAP Filter is present and Recipient Filter Type is Legacy.

How can we upgrade filter? Here is a cmdlet:

Set-EmailAddressPolicy "Default Policy" –IncludedRecipients AllRecipients

And result:



As you can see Recipient Filter is filled and Recipient Type is Precanned. Precanned means that the filter for this group was created using the pre-canned filters.

Upgrading (Default) Global Address List

Similar to Default Email Address filter only LDAP filter is present and Recipient Filter Type is Legacy.



Upgrading cmdlet with OPATH filter:

Set-GlobalAddressList "Default Global Address List" -RecipientFilter {(Alias -ne $null -and (ObjectClass -eq 'user' -or ObjectClass -eq 'contact' -or ObjectClass -eq 'msExchSystemMailbox' -or ObjectClass -eq 'msExchDynamicDistributionList' -or ObjectClass -eq 'group' -or ObjectClass -eq 'publicFolder'))}

And result:



Recipient Filter contains OPATH filter and Recipient Filter Type is Custom, since we used custom and not pre-canned filter.

Upgrading (Default) Address Lists

Notice that Default Address Lists in Exchange 2000/2003 are All Users, All Groups, All Contacts and Public Folders. All Address Lists contains only LDAP Filter and Recipient Type is Legacy.






Upgrading cmdlets with OPATH filter:

Set-AddressList "All Users" –IncludedRecipients MailboxUsers

Set-AddressList "All Contacts" –IncludedRecipients MailContacts

Set-AddressList "All Groups" –IncludedRecipients MailGroups

Set-AddressList "Public Folders" –RecipientFilter { RecipientType -eq 'PublicFolder' }

And results:







Notice that all filters are upgraded to OPATH filter format. Filters for All Users, All Groups and All Contacts were created using pre-canned filters and Public Folders with custom Recipient Filter.

This part covers converting Default Filters from LDAP to OPATH filter format. If you are using custom Email Address Lists, Global Address Lists or Address Lists please consider upgrading LDAP filters to OPATH.

Posted in: POW


POW #1 - Sending HTML e-mails to remote domains via OWA 2007

September 10, 2008 at 10:39 PM2102

As spotted on many blogs, the pretty popular topic for some time now is Links of the Week. So I decided to try something new, something more technical and useful for my readers. And here it is. New set of posts named Problem of the Week (POW).

So here is the first part that talks about sending HTML e-mails to remote domains via OWA on Exchange Server 2007, the e-mails in question being received as plain text on destination domains.

So you send 'nice' HTML e-mail...


... which is displayed in plain text at destination.


So what's the catch?

Answer lies in 'hidden' ContentType parameter of Remote Domains settings.


ContentType value MimeText is not there by default. Yes, that's right! Someone set this up on Exchange Server 2003! ;-)

Does this look familiar to you?


That's right. If you have (or had before migration) this set to Provide message body as plain text the ContectType parameter for Remote Domains is MimeText.

So what's the solution?

You need to set value of ContentType to MimeHtmlText. Here's cmdlet:

Get-RemoteDomain | Set-RemoteDomain -ContentType MimeHtmlText


...and the result...



That's all for part #1. Happy reading... ;-)

Posted in: POW


Edge Planning Tool for Office Communications Server 2007

August 25, 2008 at 2:57 PM2102

Another great tool from OCS team!

The Edge Planning Tool for Microsoft Office Communications Server 2007 provides settings for configuring your perimeter network based on information that you provide to the tool.

The Edge Planning Tool asks questions about your proposed or current edge server deployment. The tool uses your answers and Microsoft Office Communications Server 2007 best practices to generate the following reports:

  • Settings that you can use to configure your certificates, DNS services, and firewalls.
  • Custom documentation for configuring your edge servers, reverse proxy, and next hop server.
  • A comparison of your answers to Microsoft Office Communications Server 2007 best practices.




Source: Edge Planning Tool for Office Communications Server 2007

VMware Workstation faster than Hyper-V?

August 3, 2008 at 2:57 PM2102

Well... not exactly.

I came across a blog post on The Hypervisor which compares VMware Workstation and Microsoft Hyper-V.

The interesting part about benchmarks is that they are based only in difference between installation times which is complete nonsense. Hyper-V in known to be "slow" during installation (it's also slower than Virtual PC). Hyper-V shows real speed when Integrated Components are loaded.

It would be interesting to see a real (and with real I mean applications stress tests,... and not installation times) between Microsoft Hyper-V and VMware ESX. I can tell you from my test labs that VMware Workstation/Server is slow compared to Hyper-V. Anyone noticed Windows Server 2008 struggling on VMware ESX 3.5 and flying on Hyper-V? Must be something with Experimental support for Windows Server 2008 on ESX 3.5...



Source: Hyper-V benchmark surprise

Posted in:


4th Birthday

July 19, 2008 at 10:54 AM2102

Blog (at) Mreza.Info is 4 years old today. In the near future blog will be migrated to Exchange.SI domain and will also include some great online tools for every UC Administrator.











Posted in:


Cipher Suite Update for Windows Server 2003

July 17, 2008 at 1:06 PM2102

This update adds support for the following Advanced Encryption Standard (AES) cipher suites in the Schannel.dll module for Windows Server 2003:


Note: These cipher suites are based on the RC4 algorithm.



KB948963 - An update is available to adds support for the TLS_RSA_WITH_AES_128_CBC_SHA AES128-SHA and the TLS_RSA_WITH_AES_256_CBC_SHA AES256-SHA AES cipher suites in Windows Server 2003

Posted in: Windows | Security | Microsoft


Performance Tuning Guidelines for Windows Server 2008

July 10, 2008 at 10:09 AM2102

This guide describes important tuning parameters and settings that can result in improved performance for the Windows Server 2008 operating system. Each setting and its potential effect are described to help you make an informed judgment about its relevance to your system, workload, and performance goals.

This information applies for the Windows Server 2008 operating system.

What's New:

  • Added "Power Guidelines" under Server Hardware section and added "Performance Tuning for Virtualization Servers" section.

Included in this paper:

  • Performance Tuning for Server Hardware
  • Performance Tuning for Networking Subsystem
  • Performance Tuning for Storage Subsystem
  • Performance Tuning for Web Servers
  • Performance Tuning for File Servers
  • Performance Tuning for Active Directory Servers
  • Performance Tuning for Terminal Server
  • Performance Tuning for Terminal Server Gateway
  • Performance Tuning for Virtualization Servers
  • Performance Tuning for File Server Workload (NetBench)
  • Performance Tuning for Network Workload (NTttcp)
  • Performance Tuning for Terminal Server Knowledge Worker Workload
  • Performance Tuning for SAP Sales and Distribution Two-Tier Workload

Download: Performance Tuning Guidelines for Windows Server 2008 White Paper

Posted in: Microsoft | Windows Server 2008


Bash vs. Windows PowerShell

July 10, 2008 at 8:57 AM2102

Is Bash better than Windows PowerShell? Is Windows PowerShell better than Bash? Well... It depends on your needs and system you are administering. I just found first good comparison of both products.

Marcus Nasarek wrote great comparison article of Bash vs. Windows Powershell for Linux Magazine!

Posted in: Windows | Linux


Hyper-V Maximum Supported Configurations

July 10, 2008 at 8:34 AM2102

Nick MacKechnie posted a great post about Hyper-V maximum supported configurations.


  • Operating System Requirements
  • Hardware Requirements
  • Virtual Machine Architecture Support
  • Memory
  • Processors
  • Networking
  • Physical Storage
  • Virtual Hard Disks
  • Virtual Storage Controllers
  • Virtual Storage
  • Virtual CD/DVD
  • Virtual Serial (COM) Ports
  • Virtual Floppy Drive
  • Number of Virtual Machines