2 TB: Using GUID File Allocation Tables (GPT GUID Partition Table)

2 TB Drives have been around a while and certainly building raid arrays over 2 TB has been possible for quite some time. If you haven’t stumbled across this read on.

Why GPT?

  • GUID Partition Table disks can grow to a very large size. As of July 2001, the Microsoft implementation supports a hard disk of up to 18 EB (Exabyte equal 1000 Terabytes). It is not that I am predicting Exabyte drives soon but more that Master Boot Record tops out at 2 TB. GPT is the partition table to use if you plan on exceeding 2 TB.
  • How big can a GPT disk be?
    In theory, a GPT disk can be up to 2^64 logical blocks in length. Logical blocks are commonly 512 bytes in size. The maximum partition (and disk) size is a function of the operating system version. Windows XP and the original release of Windows Server 2003 have a limit of 2TB per physical disk, including all partitions. For Windows Server 2003 SP1 Windows XP x64 edition, and later versions, the maximum raw partition of 18 exabytes can be supported. (Windows file systems currently are limited to 256 terabytes each.)

More Information:

Microsoft has a Knowledge Base Article FAQ around GPT:

Microsoft has another article covering:
How to set up dynamic boot partition mirroring on GUID partition table (GPT) disks in Windows Server 2008

Jeff Loucks
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Outlook 2010: How to change your default Contacts Address Book

Have you ever wondered how to change the default address book in Outlook when you are using Exchange. If you have ever sent an email and tried to find your contacts using the To: button you know that by default the Exchange Global Address Book is the first source of contacts. What a pain.

I always find it difficult to locate where to change the default so I thought I would post it in case you are looking. I know I will come back to this post because even after having found it, I still can’t remember how to do it. It is just one of those things that has never been intuitive.

Here are the steps:

  1. From Outlook 2010.
  2. Select Contacts in the navigation pane,
  3. Ensure the Home tab is selected.
  4. Select Address Book from the ribbon.
  5. The Address Book: Global Address List windows will open
    1. Select the Tools Menu
    2. Select Options
    3. The Addressing Window will open
      1. Choose Start with contact folders
      2. Select OK
    4. Close the Address Book: Global Address List  window

From now on when you click the To: button your default address list will be the outlook contacts folder. If you don’t remember how to do it in the future, remember you found it here. I know I will be back to this post the next time I have to do this

Jeff Loucks
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Small Server Room Design: Cooling for Seasonal and Sub-Zero Climates

A client of ours is currently going through not only an unseasonably cold snap but some of the coldest weather in the history of the North West, USA. His server room is well designed with cooling for the summer but who would have thought that cooling would fail in the fall and winter months. Yet it is, and with AC down his server room only takes 15 minutes to rise in to the 90s F. So he is left with the choice of securing his server room or cooling his server room by opening the door. It is a no win situation.

So why does this happen? Most A/C units don’t work below 20 F (-7 C) and so they kick out. The solution is to change the cooling method from summer to winter. Now it depends on the size of your server room and the type of servers you are running but the following is a couple of rules of thumb that apply to any server room design where the server count is less than ten.

Three methods for Winter Cooling:

Using fans and door vents (Outside Temperature 15 C to -40 C or 60 F to -40 F and lower).

In general you can use the waste heat from your server room to supplement heating your office. This is a very efficient and often involves minimal expense. The method involves using bathroom fan or similar forced are fan to blow air into one of three places. Talk to your HVAC specialist to help you size the size of fan required. In general bathroom fans are designed to turn over air 8 times per hour and you would want about double that to keep the heat in check. Also remember that this is for continuous operation so make sure the solution you use is capable of  that type of usage. Furthermore, consider using larger diameter fans for quieter operation. To ensure proper air flow ensure a door or wall vent is installed near the floor and that the fan is installed directly above the server exhaust fans. For hotter rooms consider channeling server exhaust heat. Thermostats may be used to control fan speeds and you should size your fans for warmer outside temperatures since the air flow required to cool will be higher when the outside temperature is higher. As the outside temperature decreases the maximum cooling effect will occur directly offsetting your heating costs.

  1. General Office Space (Do not place exhaust heat near thermostats)
  2. Colder rooms or warehouses (Do not place exhaust heat near thermostats)
  3. Cold Air Return for your heating system.

If your servers are producing too much heat you may have to use AC and lower the fans CFM in order to not over heat the other areas of your office. This may mean that the outside temperature at which you use the method must be lower.

Using Outside Air, Fans and Thermostats (Outside Temperature 10 C to -40 C or 50 F to -40 F and lower).

Outside Air has a couple of problems. The first is that the humidity is variable and the second is that the temperature is variable. This requires thermostats to control the intake of outside air. Air that is 100% Humid at 10 C(50 F) is 50% humid at 20 C(68 F). So if it is raining outside at 10 C your air is just barely dry enough to cool your server room by the time it warms up to 68 C by mixing with your hot server air. People often combine this method with AC working in dehumidifying mode to keep moisture in check. As the outside temperature drops the air gets drier until it reaches zero humidity at freezing. Many people only use this method when the temperature outside reaches freezing to alleviate any concerns about humidity. The advantage of this method is that it has unlimited cooling potential so if you have a larger server room with more servers you can keep it cool by increasing the air flow.

When using this method it is important to ensure that cool dry air enters near the server air intakes and that warm air is vented from the server room either outside, into the office or into the cold air return of the building heating system. An HVAC specialist will help with ensuring proper air flow.

Using Server Room Air to warm your AC unit when it drops below -7 C or 20 F

 This method is not commonly used since it is often expensive and has limited use. In some circumstances, people have been known to create venting systems which keep the air around the AC unit above 7 C or 20 F. I will not dedicate much time to this and you should only consider it if your HVAC specialist has specific reasons why it is required in your environment. Be sure to cover the other methods first. This method is usually only used when environmental factors such as dust or salt have a negative effect on the server environment.

I hope these methods help you achieve balance and give you some starting points in considering cooling for small server room design. Should you have more questions be sure to leave a comment or contact me directly.

Jeff Loucks
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Branch Office: Removing an RODC from AD

Well eventually you are going to remove an RODC and if you are running in a test lab sooner rather than later. Microsoft has a TechNet Article which covers removing the RODC with the claim that AD metadata is removed. I have not found that to be entirely accurate. This post reflects my experience and the additional items which needed to be removed. This post reflects how to remove the RODC when the server has been lost or stolen, or in my case restored to an earlier backup.

Note: If the RODC is still connected to the domain follow the steps in the above TechNet Article and then read on for additional information about things to check for.

I originally asked a question in the MS Partner Forums.

Here is the question:

I would like to know how one properly removes an RODC server which has been permanently removed from the domain. So the scenario is, you restore an earlier version of a backup before the RODC computer was joined to the domain. However the computer name is the same and you cannot rejoin the domain.

What is the procedure to properly remove them if they are in an abandoned state.

Paulo Lin from Microsoft Partner Forums helpfully contributed among other things:

a.    Forcefully remove AD DS on rodc. [note from Jeff: In the Restored Backup, RODC was not yet installed]

Run “dcpromo /forceremoval” on RODC.


b.    Clean up AD database for this RODC from any other working DC

How to remove data in Active Directory after an unsuccessful domain controller demotion



c.    Wait for AD replication.


d.    Promote RODC back to domain as a DC or RODC.


The steps will clean up AD account, DNS records, DC objects in configuration partition and DFS replication object all in once.

I contributed the following additional best practice notes:

First I wanted to let you know that I did remove the RODC. I then went through and did some forensics to check to see if the claim was accurate that AD Metadata and DNS records were cleaned up.

My conclusion is that only certain metadata is cleaned up while other information is not. Equally, DNS information is not entirely cleaned up. This may or may not be by design and I would have to talk to people in the Product team to get a better understanding of whether the behavior I saw was expected and desired. In my case since we were permanently removing the RODC, the behavior was not desired. In KB/216498 there was some reference to ‘Advanced optional syntax with the SP1 or later versions of Ntdsutil.exe’. In this section, which is the method I would recommend, it talks about DNS and DHCP records which need cleanup.

Here is a list of things that were not removed when I followed the NTDSUtil steps from the article.

AD Sites and Services => Default-First-Site-Name ==>Servers
Server was still listed
DNS Entries
=>Forward Lookup Zones
=>Forward Lookup Zones
DHCP Entries (For Site-Site VPN)
Address Leases would eventually expire however you need to manually remove them if you want them to be realocated.
System Center Essential
Systems Center may still report computers as not connected

Jeff Loucks
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Scripting NTDSUTIL

NTDSUtil.exe is an Active Directory Utility which is used for a number of administrative tasks. In my blog I have talked about a number of administrative tasks such as defraging AD, removing AD objects and so on. Using scripts is some times easier and for that I have included a reference to a TechNet article which although short shows how easy scripting for this tool is if you know the commands you want to run.

How to automate Ntdsutil.exe using a script


Here are some examples from the article:

In the long form the following script returns a list roles held by the server:

c:\ntdsutil roles “select operation target” “connections” “connect to server servername” quit “list roles for connected server” quit quit quit

In the short form, the following script performs the same action as above however it uses abbreviated commands

c:\ntdsutil r “sel o t” c “co t s servername” q “l r f c s” q q q

Here is another script to defrag an RODC database:

c:\ntdsutil “activate instance ntds” files info “compact to c:\temp”

For more information about what to do with a compacted AD database please see the following article:

RODC: How to Defrag or Compact the Active Directory Database

Jeff Loucks
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SQL Server – How to Determine Which Version

To determine which version of Microsoft SQL Server is running, connect to SQL Server by using SQL Server Management Studio, and then run the following Transact-SQL statement.

For SQL 2008, 2005, 2000:

SELECT SERVERPROPERTY(‘productversion’), SERVERPROPERTY (‘productlevel’), SERVERPROPERTY (‘edition’)

The following results are returned:

  • The product version (for example, 10.0.1600.22)
  • The product level (for example, RTM)
  • The edition (for example, Enterprise)

For example, the results resemble the following.

10.0.1600.22 RTM Enterprise Edition

The following table lists the Sqlservr.exe version number.

Release Sqlservr.exe
SQL Server 2008 RTM 2007.100.1600.0
SQL Server 2008 Service Pack 1 2007.100.2531.0
SQL Server 2005 RTM 2005.90.1399
SQL Server 2005 Service Pack 1 2005.90.2047
SQL Server 2005 Service Pack 2 2005.90.3042
SQL Server 2005 Service Pack 3 2005.90.4035

With SQL 2000 the data will appear as follows:

8.00.534 SP2 Standard Edition
RTM 2000.80.194.0
SQL Server 2000 SP1 2000.80.384.0
SQL Server 2000 SP2 2000.80.534.0
SQL Server 2000 SP3 2000.80.760.0
SQL Server 2000 SP3a 2000.80.760.0
SQL Server 2000 SP4 2000.8.00.2039


For more Information including SQL 7 see the following KB:


Jeff Loucks
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Windows 7: What to do if you can’t find a driver

I am not one to plug companies I wouldn’t use. So know this first, I have used Driver Detective. Some people out there will be upgrading to Windows 7 and will run into problems finding a driver. Now when I ran into the this problem in the early betas of Windows 7 I spent time looking for drivers online. I used some pretty specific techniques that everyday users would find impressive but I say are just plain time consuming. And I don’t have time for it.

So for that reason I would like to introduce you to one of the greatest time savers I have ever found. Driver Detective. Sure the product once installed may be over zealous in trying to find the absolute latest driver for everything causing you an on going administrative workload that is completely unjustified, however if you can’t find a driver or your device is not working quite right, it is a jewel.

Visit the site here: http://www.drivershq.com/

It is worth the price to get something working if you really have exhausted your patience.

Jeff Loucks
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48-Core Intel Processor – Leveraged by Barrelfish

Intel has released a research chip with 48 cores. Called a single-chip data center, its core selling point is that it uses dramatically less energy. What I noticed is that its new architecture leverages software memory control and messaging. As you will remember from my previous post on Barrelfish and next generation Windows, this architecture is designed without hardware level memory control allowing the operating system to control the use of cores and memory alleviating the current bottlenecks on performance.

Those folks in the barrelfish project are slapping their lederhosen and clearing their throats with Ricola about this technology. “We’re very excited about Intel’s Single-chip Cloud Computer. In the Barrelfish project we are designing OS architectures for future multi-core and many-core systems. The chip’s memory system and message passing support are a great fit for us, and it’s an ideal vehicle for us to test and validate our ideas.” – Prof. Timothy Roscoe, ETH Zurich

This is exciting progress as the path toward future operating system performance increases becomes clearer.


Barrelfish in previous posts: http://msmvps.com/blogs/jeffloucks/archive/2009/10/01/big-engine-no-gas-multi-core-os-with-native-support-for-the-hardware-we-buy-still-a-future-prospect.aspx

Intel Press Release: http://www.intel.com/pressroom/archive/releases/2009/20091202comp_sm.htm

Jeff Loucks
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