Monday, February 16, 2009

Help, my database is corrupt. Now what?

A corrupt database is probably one of most DBA's worst nightmares. It results in downtime, managers shouting and all other sorts of unpleasant things

In this article, I'm going to explain some of the things not to do to a corrupt database, and then go through some of the things that should be done, some of the scenarios and the fixes for those.

Thursday, February 12, 2009

Microsoft Hyper-V Server 2008 Configuration Guide

Detailed setup & configuration guide for Microsoft Hyper-V Server 2008.

Planning for Hyper-V Security

Once you have updated the Windows Server® 2008 operating system with the Hyper-V™ technology release bits and enabled the Hyper-V role, you are ready to run virtual machines (VMs) on your server, now called a virtualization server (also called a “host”).

How does this change your security? Not much. Hyper-V is designed to be fairly transparent. You secure your VMs the same way that you secure physical machines. For example, if you run antivirus software on the physical machine, run it on the VM (not the host). If you segment the physical server to a particular network, do the same to the VM.

Securing the virtualization server itself involves all the measures you take to safeguard any Windows Server 2008 server role, plus a few extra to help secure the VMs, configuration files, and data. 

Achieving High Availability for Hyper-V

Server virtualization is poised to make a significant impact in enterprise IT departments, and Hyper-V with Windows Server 2008 can make it a reality. The consolidation of servers onto fewer physical machines has huge advantages in resource and cost savings, but two key factors need to be considered during the planning process. Users have increasing expectations regarding the availability of their software, including both line-of-business (LOB) applications and tools such as messaging and collaboration platforms. Furthermore, problems or failure on servers can have a significantly greater impact on operations. Windows Server 2008 and Hyper-V provide solutions that can be implemented to provide high availability (HA) of virtual machines (VMs) as well as to the workloads being hosted inside the VMs.

An Introduction to Hyper-V in Windows Server 2008

There has been quite a lot of talk about virtualization recently, and most of the discussion is specifically about server virtualization. This is one of the most exciting trends in the industry and one that has the potential, over the next few years, to change the paradigm of how IT systems are deployed. But server virtualization will not only change how IT administrators and architects think about servers and system utilization, it is also going to affect the processes and tools used to manage what will certainly become an increasingly dynamic environment.
Virtualization has actually been around for some time now, but the technology is still evolving. In fact, the word itself still means different things to different people. In broad terms, however, virtualization is about abstracting one layer of the technology stack from the next layer, like storage from servers or the OS from the applications. Abstracting the different layers, in turn, enables consolidation and better manageability.
As a concept, virtualization applies to storage, networks, servers, applications, and access. When you look at storage and networks, the goal of virtualization is to aggregate a set of different devices so the total pool of resources looks and acts like a single entity. For example, you can configure a 40TB storage solution instead of a set of 20 2TB storage devices. But with other components, virtualization acts in the opposite direction, helping you to make a single system appear as though there are multiple systems. The most common example of this is server virtualization, where you host multiple OS instances and environments on a single server.
Microsoft has approached virtualization at several different levels, extending from the desktop to the datacenter with solutions for server virtualization, application virtualization, presentation virtualization, and desktop virtualization. The common thread across all of these is the management piece with Microsoft System Center. For this article, I am focusing on the server virtualization component and specifically on how Hyper-V, a key feature of Windows Server 2008, fits into the equation for a dynamic datacenter.

Tuesday, February 10, 2009

Installing and Configuring Openfiler with DRBD and Heartbeat (HA Cluster Setup)

Openfiler is a high performance operating system tailored for use as a SAN/NAS appliance. This configuration will enable two Openfiler appliances to work in an Active/Passive high availability scenario.

Right click to mount/unmount VHD in Windows 7 or Windows Server 2008 R2

Tool to mount / unmount VHDs by right clicking on a VHD file. This new tool will work on Windows 7 or Windows Server 2008 R2 systems with or without Hyper-V role. This one uses diskpart commands available within this new OS and hence there is no dependency on Hyper-V WMI interfaces. So, you can use this new script only if your system has Windows 7 or Windows Server 2008 R2.

Windows Image to Virtual Hard Disk Converter (WIM2VHD)

WIM2VHD is a tool that will create a bootable VHD from a specified Windows 7 or 2008 R2 WIM image (like the INSTALL.WIM file that ships on the installation DVDs) without having to run Windows Setup.  That means that you can a Windows 7 or Windows Server 2008 R2 virtual machine up and running much, much faster.

Powering Server Core - Configuring UPS Devices

Microsoft Windows Server 2003 and Microsoft Windows Server 2003 R2 came with built-in support for serial and USB connected Uninterruptible Power Supply (UPS) devices. From within the Power Options you could manage your UPS and the shutdown behavior of the box.

About UPS Devices

UPS devices help prevent loss of data from power loss (“black-outs) by shutting down the server properly instead of abruptly. The device also helps protect the server hardware from power surges, brown outs, drop outs and voltage fluctuations, extending the life of the hardware.

Continues on...

Monday, February 9, 2009

HOWTO Configure iSCSI CHAP authentication on Microsoft iSCSI Initiator

OpenFiler's implementation of CHAP doesn't seem to work the same as other products I have used (in terms of what you see on the client end).  However, this isn't to say that OpenFiler is implementing it incorrectly, for all I know the other products were!

So, here goes:


First off, I am not going to detail how to install OpenFiler or how to set up a basic disk and turn on iSCSI.  Information on installing OpenFiler can be found in the documentation and David Davis posted a nice article here about how to set up a basic volume for iSCSI use.  I am also not going to discuss how to instal the Microsoft iSCSI intiator, although it is very easy to do and can be downloaded here.

Once you have set up Open Filer for basic iSCSI access and have installed the MS iSCSI Initiator, perform the following steps:

Friday, February 6, 2009

Windows Server 2008 Hyper-V Security Guide – beta now available

For organizations that seek cost-effective operations, the benefits of virtualization are more evident than ever. Microsoft® Hyper-V technology allows consolidation of workloads that are currently spread across multiple underutilized servers onto a smaller number of servers. This capability provides you with a way to reduce costs through lower hardware, energy, and management overhead while creating a more dynamic IT infrastructure.

Virtualization technologies are causing enterprise organizations to shift their thinking about IT. The Hyper-V Security Guide can help you elevate the security of virtualized Windows Server® environments to meet your business-critical needs. This accelerator provides IT professionals like you with recommendations to address your key security concerns around server virtualization. The guide provides authoritative guidance that relates to the following strategies for securing virtualized environments.

Installing Windows Hyper-V Server 2008

How to install Microsoft Hyper-V Server 2008 and use the HVConfig command line configuration tool.

Microsoft Hyper-V Server (HVS) 2008 is a hypervisor solution that is based on Windows Server 2008 and Hyper-V. Unlike Windows Server 2008 which supports the installation of many different roles, Microsoft Hyper-V Server 2008 is standalone virtualization software that does not support any additional roles.

The installation of Microsoft Hyper-V Server 2008 will be very familiar to those of you who have installed a Windows Server 2008 edition because it uses a similar wizard-driven installation. Here are the steps you must follow to install Microsoft Hyper-V Server 2008.

A closer look at the Windows 7 SKUs

Today, I wanted to take a closer look at the Windows 7 SKUs since there has been some discussion about them for the last couple of days. By the end of this post, I want you to know exactly which edition of Windows 7 is right for you and help you understand how we approached addressing the large amount of feedback we received.

Our SKU line-up is based on listening to feedback from customers and partners and here is what they have told us and how we are addressing their feedback in Windows 7:

Customers wanted clarity on which version of Windows is the right version for them.  So…Windows 7 will be offered primarily in 2 editions: Windows 7 Home Premium and Windows 7 Professional.

Continues on...

Tuesday, February 3, 2009

Disk Subsystem Performance Analysis for Windows

Analyzing storage subsystem performance is an art, not a science. Each rule has an exception; each system designer or administrator has a different combination of hardware configurations and software workloads to consider. This paper examines the performance of storage subsystems used by computers running the Microsoft Windows 2000, Windows XP, or Windows Server 2003 family of operating systems.
This paper considers performance from both the hardware and software perspectives. In addition, it discusses tools for storage subsystem analysis and design and provides rules of thumb and guidelines for system design and to solve the performance bottlenecks in specific configurations.

Exchange - How to Calculate Your Disk I/O Requirements

Calculating your disk I/O requirements ultimately allows you to optimize your disk subsystem to best support your users.
Your goal is to provide enough disk I/O performance (measured by the number of I/O operations per second [IOPS] that can be performed) with acceptable latency that allows for efficient Exchange functionality.
Calculating the IOPS per mailbox is a convenient way to measure the profile for a given server based on random database read/write I/O (transaction log I/O is not factored into this equation). The higher the IOPS per mailbox, the more aggressive the mailbox profile is in terms of disk usage.

SQL Server CLR function to improve performance of validating email addresses

When you send e-mail to large lists, validating the e-mail addresses before sending out the e-mail is worth doing to prevent having mail rejection messages clog up your mail server. I had been doing the validation with a T-SQL User Defined Function (UDF), but it was getting too slow as the number of e-mails grew. I needed a faster alternative, what options do I have?

Is it true that Hyper-V Server 2008 R2 will support clustering and live migration?

Yes. Hyper-V Server 2008 R2 instances can form a cluster, which enables live migration. This is a change from the initial version of Hyper-V Server, which is based on Windows Server 2008 R1 Standard Edition and couldn't be clustered.

There are still advantages to using Windows Server 2008 R2 Enterprise Edition over Hyper-V Server 2008 R2 instances, including:
  • Four virtual machine licenses are included with Enterprise edition. Hyper-V doesn't come with any.
  • You can only use the command line and PowerShell to manage Hyper-V Server locally, though you can use the full cluster GUI to remotely manage a Hyper-V Server cluster.
  • Clustering in Hyper-V Server 2008 R2 only supports Hyper-V high availability. You can't make any other applications or services highly available on Hyper-V Server 2008 R2.

Native VHD booting on Windows 7 or Windows Server 2008 R2

If you have been testing Windows 7 or Windows Server 2008 R2, you must have come across native VHD booting feature. This allows us to boot OS from VHD file residing on the hard drive. You don’t need a Hypervisor to boot from VHD. Windows 7 boot architecure changed a bit to accomodate this. In fact, Windows Server 2008 has the option to boot from a file.