Windows Server 2008 Failover Clustering Virtual Lab

Filed under: Failover Clustering 2008 — Administrator @ 10:04 pm

Microsoft posted a virtual lab today for Failover Clustering. This lab walks through the following procedures:

Adding a second node to a cluster
Creating a File Share in the cluster
Creating a Print Share in the cluster
Configuring Failback Policies
Installing WINS in the cluster
Installing DHCP in the cluster
Bonus - Adding Physical Disk resources to the cluster

You can get to the virtual lab here: http://msevents.microsoft.com/CUI/WebCastEventDetails.aspx?EventID=1032345932&EventCategory=3&culture=en-US&CountryCode=US

The lab should take about an hour to an hour and a half to complete. That, of course, depends on how many times you get interrupted with the kids wanting you to take them to the store to buy candy.

I went through part of the lab, and it looks like it will work just fine for everyone except it will not pass validate. This is because of an issue that seems to have come up in the June CTP.

BTW, I recorded a step-by-step today using Camtasia. I will probably put it someplace on the web for download early next week. Keep an eye out for it.

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Upper and Lower and Mixed Case in SQL Cluster

Filed under: Server Clustering 2003, SQL — Administrator @ 9:55 pm

I had a well known geek in my cluster class last week. Ben Miller, a former Microsoft MVP lead and SQL expert sat our cluster class, www.clusterhelp.com.

During our many conversations, Ben told me about a problem he ran into recently in SQL Server 2005 clustering. Basically, the issue is that the way the server names were recognized differed depending on what tool pulled the name since the different applications did not pull the name from the same place in the registry. So, if one node was all upper case, and the other node was mixed case or lower case, clustering would install and work just fine. However, SQL Server 2005, which pulls the name from a completely separate key in the registry, does not install properly unless both nodes are all upper case.

Ben says he is going to blog more about the issue after he has a chance to do some further testing and documents the issue completely. During class, he was able to replicate the problem with complete predictability.

See Ben Miller’s blog for more detail.

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Building a Windows Server 2008 Failover Cluster - finally!

Filed under: Storage, Failover Clustering 2008 — Administrator @ 10:15 pm

I have been dying to get my first Windows Server 2008 Failover Cluster built. Of course, I want to do it on the cheap. That means using virtualization. The problem is that Virtual Server 2005 R2 does not provide support for Serially Attached SCSI (SAS) and there is just a complete dearth of virtualized SANs out there with virtualized HBAs. OK, that isn’t going to happen anytime soon.

So, my first Failover Cluster didn’t have any shared disks. That makes it pretty worthless for testing.

Microsoft, though its acquisition of Stringbean Software (WinTarget), put an iSCSI target into the new version of Windows Storage Server, but it has not been released and is not available outside of Microsoft. So, Microsoft has been the only real source of testing outside of using real hardware.

Well, our partner, Rocket Division Software, is in the final stages of upgrading their iSCSI target software (Starwind) to support persistent reservations. It works wonderfully, so it should be released pretty soon. The only problems I have found have to do with a user interface issue that they already know about.

Anyways, now I have my first Failover Cluster using iSCSI. It passed the validate tests and runs like a charm.

Keep an eye out for Rocket Division’s release and then you will be able to try it, too.

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Standby Continuous Replication for Exchange Server 2007

Filed under: Server Clustering 2003, Exchange — Administrator @ 10:14 pm

As previously discussed, when SP1 for Exchange Server 2007 ships, it will include some new technologies, too. One is Standby Continuous Replication (SCR). I am completely psyched by this new technology.

Myself, I see SCR as the perfect remote site Disaster Recovery solution for Exchange Server 2007. What would make it the perfect solution would be having a hot site available for the implementation.

Please read more about SCR on the Exchange Team’s blog. Scott Schnoll wrote a wonderful post about it last week. I am sure you will love it, too.

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Windows Server 2008 Failover Clustering - The New Quorum Model

Filed under: Quorum — Administrator @ 11:14 pm

One of the big changes in Windows Server 2008 Failover Clustering is the new quorum model. In Windows Server 2003, we had only two choices, either the single disk quorum that has been around since NT 4.0 or Majority Node Set (MNS). Actually, there are three if you consider MNS with the File Share Witness (FSW) as a separate option.

In Windows Server 2008 Failover Clustering, administrators now have four choices on how to implement the quorum.

One option is to use Node majority. In this option, a vote is given to each node of the cluster and the cluster will continue to run so long as there are a majority of nodes up and running.
A second option is to use both the nodes and the standard quorum disk. In this option, a common option for two node clusters, each node gets a vote and the quorum, now called a witness disk) also gets a vote. So long as two of the three are running, the cluster will continue. In this situation, the cluster can actually lost the witness disk and still run.
A third option is to use the classic/legacy model and assign a vote to the witness disk only. This type of quroum equates to the well known, tried, and true model that has been used for years.
A fourth option, is, of course, to use the MNS model with a file share witness.

It has been a few days since I have seen the GUI, so I can’t tell you off the top of my head which order they appear in within the GUI.

Two notes that caught my attention the other day when talking about these options is that it is not possible to use DFS as the file share witness and with changes to the quorum there aren’t any checkpoints so there is no longer a need for the -resetquorumlog switch on starting the cluster service.

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Windows Server 2008 Failover Clustering - Storage Changes

Filed under: Server Clustering 2003, Storage, Network, Quorum — Administrator @ 11:13 pm

In a previous blog, I talked a little bit about some of the major changes to disk storage for Windows Server 2008 Failover Clustering. Now, while I wait for dinner to cook, is a good time to cover some of the changes.

2TB Limit- The biggest change, in my opinion, has to be elimination of the Master Boot Record (MBR) requirement for clustered disks. MBR forced a limitation to the physical disk resource size of 2TB. Now, Windows Server 2008 supports the use of GUID (sometimes called Global) Partition Table (GPT) which allows up to 16 Exabyte. The practical limit is really around 160-200 TB based on today’s technology. Keep in mind that just because you can do it doesn’t mean you should do it. Can you imagine how long it would take to degrag a 100TB disk? How about reindexing it? How about chkdsk?
SCSI Bus Resets - In Windows Server 2003 Server Clustering, SCSI bus resets are used to break disk reservations forcing it to become disconnected so that another controller can take control of the disks. The problem with SCSI bus resets is that they require all devices on the same bus to lose their connection. These resets were not exactly warmly received by the disks that were impacted without any reason for it. In Windows Server 2008 Failover Clustering, SCSI bus resets are no longer used as persistent reservations are now required.
Persistent Reservations - WIndows Server 2008 Failover Clustering supports the use of persistent reservations. This means that directly attached SCSI storage will no longer be supported in 2008 for Failover Clustering. Serially Attached Storage (SAS), Fiber Channel, and iSCSI will be the only supported technology. However, not all vendors support persistent reservations, so this will be a problem as organizations move to Windows Server 2008 Failover Clustering without full and proper testing.
Maintenance Mode - In maintenance mode allows administrators to gain exclusive control to clustered disks
Disk Signatures - In Windows Server 2003 (and earlier), administrators would come to our classes at www.clusterhelp.com and would cringe whenver we talked about disk signatures. I even had one burst into tears from reliving past stress. OK, maybe not real tears. Anyways, clustering used disk signatures to identify each clustered disk. The disk signature, at sector 0, is often an issue in disaster recovery scenarios (in class I show how to totally get around disk signature issues). To make it easier, Failover Clustering makes use of SCSI Inquiry Data is often written to a LUN by a SAN. In the event the disk signature gets out of whack, the disk signature can be reset once the disk has been verified by the SCSI Inquiry Data. If for some reason, both the disk signature and the SCSI Inquiry Data are not available or are misconfigured/corrupted, an administrator can a Repair button is available on the Physical Disk Resource properties general page. The Repair button can be used to point the actual disk to the resource.
Disk Management - The virtual disk service (VDS) APIs first became available with 2003 R2. Using the disk tools in Windows Server 2003 R2 (and now 2008), an administrator can build, delete, and extend volumes in the SAN.

All in all, there have been some pretty significant changes when it comes to the way Windows Server 2008 Failover Clusters work with disk storage.

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Tech Ed 2007 - Orlando - notes from the field

Filed under: Quorum, Failover Clustering 2008 — Administrator @ 12:09 am

Its that time of year again. The masses gather to learn from the best, talk to the experts, network with others. This year I am not only speaking at the conference, I am also helping at the TCL Yellow Section - Windows Server 2008 Failover Clustering POD. Here is a sample of what people want to know:

Q. Can I upgrade from Windows Server 2003 to 2008?

A. NO! Migration is the only and best way to go.

Q. Will Exchange Server 2007 run on Windows Server 2008 Beta 3?

A. Exchange Server 2007 does not run on the Beta of Windows Server 2008. Exchange will run on Windows Server 2003 and the final (RTM) copy of Windows Server 2008.

Q. Can I cluster Virtual Machines running Microsoft Virtual Server 2005 R2?

A. Yes you can!

Q. What is really new about Failover Clustering in Windows Server 2008?

A. Great question, here is some highlights:

No service account - now uses a local system account
No support for Parallel Attached SCSI (PAS), this allows for better hardware control and failover
16 nodes if you use a 64-bit edition of Windows Server 2008
Support for GPT disks, yes larger than 2TB disks are now supported natively
Validate - ensure your systems are cluster ready and help you follow best practices
4 Quorum models, no more single point of failure for the quorum
- Majority quorum model
- Majority of Nodes
- Witness disk
- File Share Witness
Improved IPSec, no more 7 minute timeout when failed over!
Stretched clusters can have nodes in different network segments with various speeds
Cluster Migration Tool - to help you migrate
MMC 3.0 snap-in, no longer a seperate application
Setup/install 2003 was 23 steps, now 3 steps. Yes I said 3 steps

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TechEd Cluster Booth - Top Questions

Filed under: Server Clustering 2003, Storage, Network, Quorum, Virtual Server — Administrator @ 11:14 pm

The number one question by far at the cluster booth is, what are the differences between Windows Server 2003 Server Clustering and Windows Server 2008 Failover Clustering.

The major differences that I can discuss off the top of my head include:

Service Account - There is no longer a need for a service account for the cluster service. It now uses the local system account.

Validate - The new validate tool tests the complete configuration and provides a report of items that need to be fixed or a nice report saying that the cluster passed. If the cluster passes the validate test tool, it will be fully supported by Microsoft.

Quroum - The quroum has changed considerably. I will discuss these changes in a blog in the next few days.

SAN Support - This also deserves its own blog entry. Basically, there is no longer a 2TB disk limit imposed by MBR formatting. 2008 supports GPT so you can get 16 Exabyte, theoretically, but really only about 160 TB or so based on today’s tecnology. Also the nodes can use the virtual storage API to create LUNs if the storage vendor supports the APIs. Also, the new clustering technology uses persistent reservations, which is not supported by many current iSCSI implementations. Most iSCSI vendors are working to update to meet there requirements.

Configurable Heartbeat timeout - There is no longer a 500ms roundtrip limitation for heartbeat communications.

OR - Networking - The addition of the OR logic is a huge change in my opinion as now we can use the OR with two TCP/IP addresses and the addresses can be from different subnets. This option enables geo clustering without the use of a VLAN. Yes, you got that right, no more need for a VLAN for geo clustering.

Migration - Yes, the new 2008 is x64. You can not combine 32 bit and 64 bit nodes, so you can’t do a rolling upgrade from 2003 to 2008. All upgrades will have to be migrations.

Scoping - One of the complaints with 2003 was that if you had multiple file share virtual servers and they were on the same physical node, all of the shares would show up in all of the virtual servers. Now scoping allows control so these other shares are not visible.

Ease of Use - The ability to create a cluster group with its appropriate resources takes about 5 screens and you are done. It is incredibly simple to cluster resources now. I will provide a comparison in a blog in the next week or two.

The second most asked question appeared (yeah, yeah, I didn’t bother actually tracking) was about Virtual Server 2005 R2 and whether virtual servers could be clustered. The answer is yes, they can be clustered. The process is called Host clustering since the host machines are clustered, and the virtualized servers can be moved (or failed) over to other hosts. You can read all about it at http://technet2.microsoft.com/windowsserver/en/library/9a3de6d0-c820-41ac-860c-de950d271f8d1033.mspx?mfr=true.

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eLearning - Failover Clustering

Filed under: Server Clustering 2003 — Administrator @ 11:15 pm

Microsoft recently published a two hours online course on Failover Clustering for Windows Server 2008 (formerly known as Longhorn).

You can access this content here and for $39.99, you can spend as much time as you want for the next three years reviewing the content.

This course, Course 6051: Implementing High Availability and Virtualization in Windows Server 2008 is part of a larger group of courses that can be purchased as a group, or you can purchase this individual course separate from any other eLearning course.

Rod Fournier and I are working on very similar material, with much more depth for our ClusterHelp.com course. However, we will not be releasing it until Windows Server 2008 is released to manufacturing. Look for more information here as Windows Server 2008 comes closer to release.

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How to create a scheduled task within a Windows 2000/2003 Cluster

Filed under: Server Clustering 2003 — Administrator @ 12:10 am

You have a need to run a procedure on the active node within a cluster. This procedure needs to occur at the same time each day. This procedure needs to run only on the active node for a given group. You are not alone; this is a very common request. The not so easy answer is below.

Modify Scheduled Jobs default location on all nodes

By default the scheduled job information is located in %systemroot%\tasks subdirectory. To work within a cluster the location needs to move to the shared disk.

Modify the following registry key so that the tasks folder location is pointed to the tasks subdirectory on the shared disk. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SchedulingAgent

This key has the following value: TasksFolder reg_expand_sz
%SystemRoot%\Tasks (change this path to task directory on the shared disk, I suggest you create a dedicated directory)

NOTE: There may be an issue performing the work and test from a terminal server session as the jobs may initially fail. Log off and back on terminal server (see KB 232276) and then the jobs will work.

Create the task on the active node in the cluster:

Go to Start-> Control Panel -> Scheduled Tasks -> Add Scheduled Task. Follow the prompts, for Application use the path to the batch file or program. Make sure you store the batch file or program on the shared disk.

Create a resource within the cluster:

1. Go into HKLM\SYSTEM\CURRENTCONTROLSET\SERVICES and write down the exact
name of the service as it shows in the list as you will need this for later. In this case it will be Schedule, but you could use this process for any service.

2. Go into Cluster Administrator and highlight the group you want to put this in and then right click on the group and choose New and Resource.

3. In the Name box, input whatever you want shown in Cluster Administrator, in the Description box, put whatever you want if anything or leave it blank, for the Resource Type field, choose Generic Service, in the Group field, it should already have the group you want and click Next.

4. Make sure that all the nodes are listed as Possible owners and choose Next.

5. For dependencies, add the Disk and the Network Name and choose Next.NOTE: The Task Scheduler Generic resource must also be setup with a dependency on the physical disk and network name to prevent the resource from starting before the other resources are online.

6. For the Service Name field type Schedule, (or exactly what you wrote above for the name of the Service if different). If it does not identically match, the service will fail to come online. For the Startup Parameters type %SystemRoot%\System32\svchost.exe -k netsvcs (you would normally leave this blank. If the Service requires any parameters, it is generally in the registry for the service) and select the Use Network Name check box and choose Next.

7. For the registry key, go ahead and add the complete exact path to the registry. HKEY_LOCAL_MACHINE is a given, so you would use SOFTWARE\Microsoft\SchedulingAgent and then click OK and then Finish.You can bring the resource online at this point. The Task Scheduler is changed from Automatic to Manual during the above process. If it is not, ensure that every node has the service set to manual.

Important Note for the remaining node(s):

The security credentials for each job are contained in the Protected Storage Database on the local node and not with the job. So in order for a job to work on all nodes you need to refresh the credentials of the job on each node. To do that, create the job on first node, set the credentials.
Move the generic service resource to the 2nd node and enter the credentials for the job again. This issue is discussed in the following KB 317529 – Scheduled Task Does Not Run When You Push It to Another Computer.

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The Best of Russ and Rod

July 20, 2007

Windows Server 2008 Failover Clustering Virtual Lab

July 18, 2007

Upper and Lower and Mixed Case in SQL Cluster

July 6, 2007

Building a Windows Server 2008 Failover Cluster - finally!

July 3, 2007

Standby Continuous Replication for Exchange Server 2007

June 12, 2007

Windows Server 2008 Failover Clustering - The New Quorum Model

Windows Server 2008 Failover Clustering - Storage Changes

June 6, 2007

Tech Ed 2007 - Orlando - notes from the field

June 5, 2007

TechEd Cluster Booth - Top Questions

June 2, 2007

eLearning - Failover Clustering

May 25, 2007

How to create a scheduled task within a Windows 2000/2003 Cluster

Modify Scheduled Jobs default location on all nodes

Create the task on the active node in the cluster:

Create a resource within the cluster:

Important Note for the remaining node(s):