Tag: Windows

Using PowerShell To Set Resource Owners In A Cluster

Following up on my post about Using PowerShell To Add Owners For Cluster Disks here’s another quick post on how PowerShell can help you with your clusters.

In my new cluster build out I needed to quickly set it so that one of the SQL instances could only potentially live on two of the 5 nodes. This could have been quickly done using the GUI however it’s just as fast to do so using PowerShell.

Load up the Windows PowerShell Modules and you’re ready to go.

 

In this example we have a two node cluster made up of SERVER1 and SERVER2 and a single installed SQL instance called INST1.

In PowerShell the following would provide us a list of possible owners of INST1:

Get-ClusterOwnerNode -Group "SQL Server (INST1)"

ClusterObject                          OwnerNodes                                 
————-                                 ———-                                 
SQL SERVER (INST1)           {server1, server2}
         

 

Now to change this so that only SERVER1 can potentially own the SQL instance is a very quick task:

Set-ClusterOwnerNode -Group "SQL Server (INST1)" -Owners SERVER1

 

Sadly you don’t get any feedback that the change has been made, but if you run Get-ClusterOwnerNode again:

Get-ClusterOwnerNode -Group "SQL Server (INST1)"

ClusterObject                          OwnerNodes                                 
————-                                 ———-                                 
SQL SERVER (INST1)           {server1}
       

 

Adding SERVER2 back is as quick as running Set-ClusterOwnerNode again and providing a comma delimited list of servers:

Set-ClusterOwnerNode -Group "SQL Server (INST1)" -Owners SERVER1,SERVER2

ClusterObject                          OwnerNodes                                 
————-                                 ———-                                 
SQL SERVER (INST1)           {server1, server2}
     

 

You have to love the simplicity of working with clusters in PowerShell.

Using PowerShell To Add Owners For Cluster Disks

Here’s a quick post about how great PowerShell can be for your clusters.

I’m in the middle of configuring a few machines in clusters and recently added a new node to a cluster that was already built (but not configured). I needed to have that final node be a possible owner for all 33 presented disks on that cluster.  To do that through the cluster GUI would require a heck of a lot of mouse clicks….PowerShell to the rescue!

The Windows PowerShell Modules (under Administrative Tools) allow you to do all kinds of wonderful things with clusters.

Allowing a single disk to be owned by the extra server is as simple as:

CLUSTER RESOURCE "Cluster Disk 1" /addowner:DBSERVER1

 

 

If I want to do that for 33 disks a quick PowerShell one-liner takes care of it:

$i=1;do {cluster resource `"Cluster Disk $i`" /addowner:DBSERVER1;$i = $i +1} while ($i -lt 33)

 

 

Here’s a version that’s a little more readable:

$DiskNo = 1

DO

    { CLUSTER RESOURCE `"Cluster Disk $DiskNo`" /addowner:DBSERVER1

        $DiskNo = $DiskNo+1

    }

    

WHILE ($DiskNo -lt 33)

 

Quick and easy. Saved my clicky finger lots of work.

 

More PowerShell and cluster fun coming up in the next few weeks.

MSDTC Failing In A Cluster

I’m merrily working away on installing SQL 2008R2 on a bunch of new clusters. The SQL installs have gone fine and I’m getting set to install MSDTC, one for each SQL instance (read the awesome post by Cindy Gross on this).

The install of MSDTC went smoothly and it seemed very happy. Then I failed over the cluster…

MSDTC failed.

It wouldn’t restart.

I failed back to the original node and it wouldn’t start there either.

 

What’s the error?

I dumped the last few minutes of the cluster log by opening a dos box command prompt and running…

cluster log /gen /span:5

 

This dumps the last five minutes of cluster logs into C:WindowsClustercluster.log

I scrolled through to get to the MSDTC error piece:

INFO  [RES] Physical Disk: Failed to get vol MP root for path ?, status 123
ERR   [RHS] Error 123 from ResourceControl for resource <instance>_MSDTC.
WARN  [RCM] ResourceControl(STORAGE_IS_PATH_VALID) to <instance>_MSDTC returned 123.

I checked the disk resource for MSDTC and it was online. Looking at the filesystem on that disk and there was an MSDTC directory, so I knew there were no access problems. It didn’t make any sense.

 

So what’s going on?

The key error here is the failure to get MP root for path ?

Apparently MSDTC is not supported does not work with Mount Points, which is what I had set the dependency to. There were no warnings on this when setting MSDTC up and I’d not seen or heard of any documentation that speaks to this.

I was finally pointed to a Connect item opened by someone who’d had the same issue https://connect.microsoft.com/SQLServer/feedback/details/576545/msdtc-fails-to-restart-in-sql-server-2008-r2-clustered-group

Side note: I love it when Connect items such as this are closed as by design. Why is this by design? Can someone explain to me why MSDTC shouldn’t be supported on Mount Points?

 

I deleted the MSDTC resource and added it again, this time using a regular drive as a dependency and everything worked perfectly. I was able to failover and have SQL perform distributed transactions.

Be Careful Installing Windows Features

Did you know that installing certain Windows features could impact the way that SQL gets installed on your server? Me either.

When performing some installs recently I came across a problem whereby I was not able to change the shared tools location. The option was greyed out. This didn’t make any sense to me. The install was happening on a new server, there had been no previous SQL installs on the machine and so no problems with installed components preventing those kinds of problems.

 

Digging through the filesystem I found a C:Program FilesMicrosoft SQL Server folder. That didn’t make any sense to me at all, I’d not installed anything.

I could not even find anything that might be using this folder when looking through the installed software and yet I couldn’t delete the folder as there were files in use.

After much head scratching I finally found the problem.

 

I had installed the Windows System Resource Manager feature to help manage resources, which is very useful when running more than one instance of SQL on a machine, or if you have multiple software installs and want to keep control of your CPU and memory. This feature uses (and so automatically installs) another feature called the Windows Internal Database which it says is a relational data store.

 

By the looks of things the Windows Internal Database is based around the SQL 2005 engine, this gets installed into C:Program FilesMicrosoft SQL Server.

When performing the new SQL install it went out and identified that SQL components were already installed and forced installation of the shared tools into that same location.

 

After removing the Windows System Resource Manager and Windows Internal Database features I was able to move the shared tools install to another location.

Be very aware of what features and roles might be install on your machines, it might bite you when you least expect it.

SQL Clustering–Network Binding Order Warnings

In setting up my Windows 2008 R2/SQL 2008 R2 cluster this week I came across a warning in the Setup Support Rules stating that “The domain network is not the first bound network.”

 Network Binding Order Error

 

This didn’t make any sense to me as I had been very careful in setting the binding order in the network connections properties:

Binding Order Set

 

Deciding to look for further information on this I opened up the Detail.txt file from the Setup Bootstrap/Log directory and searched for network binding order:

Binding Order Setup Log

 

Strangely the first bound network is Local Area Connect* 9. I had no idea what this network was as it was not listed in the network adapter list.

I remembered a discussion on Twitter a couple of weeks ago between Allan Hirt (blog|twitter) and Denny Cherry (blog|twitter) where they talked about this exact problem and the fact that it was a hidden cluster adapter which needed to be moved in the binding order, and that had to be done in the registry.

I opened up regedit and drilled down to HKEY_LOCAL_MACHINESYSTEMCurrentControlSetservicesTcpipLinkage and opened up the Bind value:

Registry Showing Incorrect Binding Order

 

I’ve highlighted the first item in the bind order. The trouble is that this GUID value really means nothing to us…time to crack open PowerShell

gwmi Win32_NetworkAdapterConfiguration | where-object {$_.IPEnabled -eq "True"} | ft Description, SettingID -auto

List of active adapters

 

As you can see the Microsoft Failover Cluster Virtual Adapter GUID matches the first bound value. Back to the registry to move that adapter down the list with a quick cut and paste.

*Warning, playing in the registry can cause system instability, BSOD problems, singularities and quantum fluctuations*

Registry with correct binding

 

Starting up the cluster install again and the Network binding order warning is gone

 

Hopefully the next releases of Windows and SQL won’t have this problem. In the meantime this is good to know. Thanks Allan and Denny for engaging on Twitter and leading me to the answer to the problem.

Upcoming Clustering Fun

I’ve a fun week upcoming, I get to do a bunch of installs of SQL 2008 R2 on some Windows 2008 R2 clusters.

 

I’ve had a lot of experience in building and working with Windows 2003 clusters and deploying SQL 2008, this is a new era for me and means new toys to play with and new things to learn. I’m excited to really get to grips with Windows 2008 clustering, there are some significant differences between it and 2003 which is going to provide some challenges. I’m aiming to perform quite a few build up and tear downs of one cluster over the next couple of weeks to build up my levels of comfort with the newer technology, and work towards getting some nice scripts together to do so.

 

As a consequence of Windows 2008 R2 being new to me for clustering I decided to pick up Pro SQL Server 2008 Failover Clustering by Allan Hirt (blog|twitter), a Clustering MVP and guru (who has a new whitepaper out about Applying Updates to a Clustered Instance of SQL Server 2008 or SQL Server 2008 R2). Allan was on the MidnightDBA web show a couple of weeks ago (go watch it) where there was lots of conversation on several aspects of High Availability.

 

I’m still only a quarter of the way through the book but have already found out some fantastic information on things such as the network priority and installing server roles from the command line.

 

As the build goes along I plan on putting up a couple of posts to track the process and gotchas as well as a final review of Allan’s book, so check back soon.