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Archives for February 2018

Installing SQL Server 2008 R2 In A Windows Server 2012 Cluster

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A Good Read Before You Install SQL Server 2008 R2 In A Windows Server 2012 Cluster

If you want to install ANY version of SQL Server in a Windows Server 2012 environment, I highly recommend you read the following KB article.

http://support.microsoft.com/kb/2681562

In particular, I ran into this error while trying to install SQL Server 2008 R2 on Windows Server 2012 and was running into the following error (among others).

Installing SQL Server 2008 R2 In A Windows Server 2012 Cluster
Figure 1 – Rule “Cluster service verification” failed

The Solution

The fix is simple, as described in the KB article, simply enable the Failover Cluster Automation Server in the Add Roles and Features wizard or via the following Powershell command:

add-windowsfeature RSAT-Clustering-AutomationServer

That fix will resolve the other Setup Support Rules errors including the cluster validation error and any errors about cluster storage. You should be able to re-run the SQL installation and it will pass all the Setup Support Rules and allow you to continue with the cluster install.

Of course all this assumes you have slipstreamed at least SP1 onto your SQL install media. If you try to install without SP1 or later you will also run into lots of problems.

Reproduced with permission from https://clusteringformeremortals.com/2013/04/12/installing-sql-server-2008-r2-in-a-windows-server-2012-cluster/

Special Offer For Microsoft MVPS – Free DataKeeper!

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For the MVPs out there

I just got the word that this is official and we are ready to ship software…

SIOS Technology is pleased to offer Microsoft MVP Community a fully functional two NFR copies of SteelEye DataKeeper Cluster Edition (DKCE).  DKCE enables SANless failover clustering solutions using any local attached storage. It enables high speed and highly available SMB 3.0 storage solutions for SQL Server and Hyper-V.

Common use cases of DKCE include SAN-less SQL Server Failover Cluster Instances using local high speed storage solutions like Fusion-io or even building clusters in the public cloud.  Another exciting possibility is highly available file servers on Windows Server 2012 for robust SMB 3.0 storage solutions for Hyper-V or SQL Server without having to purchase a shared SAS Array or SAN. Once again, you can take advantage of the blazing speeds possible with SSD or local flash based storage without sacrificing any availability. Be the first kid on your block to migrate your Hyper-V and SQL Server to SMB 3.0 and take advantage of faster failovers and easier storage management.

 Simply email datakeeper-mvp@us.sios.com  to learn how to get started with DataKeeper Cluster Edition!

MVPs grab your copy today and let me know what you think. The forum has invited you! I am monitoring the forum and I look forward to your feedback!

Reproduced with permission from https://clusteringformeremortals.com/2013/03/07/special-offer-for-microsoft-mvps-free-datakeeper/

Are Replicated Clusters With DataKeeper Better?

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Why Replicated Clusters With DataKeeper Are Better Than Single Copy SAN Based Clusters?

If you have followed the history of clustering as closely as I have for the past 10 years as a Microsoft Cluster MVP, you will notice that Microsoft has been steadily moving away from single copy clusters. It started with Windows Server 2003 with the elimination of a shared disk quorum and the introduction of majority node set quorums and the file share witness. The complaint with clusters based on shared disk quorums was that if the quorum became unavailable or corrupt, the entire cluster would fail. This was a major complaint and it was primarily what gave clustering a bad name in the early days.

Once the shared disk quorum was eliminated, people were still left with their application data residing on the cluster which was also a problem as the SAN was still a single point of failure in a cluster, a performance impediment and a management headache. Microsoft has begun to address those concerns with the introduction of Exchange 2007 CCR and Exchange 2010 DAGs as well as SQL Server 2008 R2 Database Mirroring. Microsoft has eliminated Exchange 2010 single copy clusters entirely and SQL Server single copy clusters are only still around because they haven’t perfected SQL Server replication yet.

The Introduction of SIOS DataKeeper

Hyper-V is the most recent cluster resource supported by Microsoft clustering that does not yet have a native cluster integrated replication solution. This is where SIOS DataKeeper fits in. We first demonstrated our DataKeeper Hyper-V replication solution at the Microsoft Virtualization launch in September of 2008 and have been providing HA and DR solutions for Hyper-V since Hyper-V was first introduced. Our solution is logo certified for Windows Server 2008 R2 as well as Hyper-V.

Why DataKeeper?

DataKeeper fills the gap left by single copy clusters as shown in the table below and subsequent paragraphs. The following customer story also highlights some of the reasons why people are adopting DataKeeper in lieu of SAN based solutions.

http://www.computerweekly.com/news/2240177361/University-shuns-HP-array-features-for-SIOS-host-based-replication

Are Replicated Clusters With DataKeeper Better?

Eliminates single point of failure

A SAN is a single entity made up of redundant pieces. To have a truly redundant SAN you need redundant controllers, power supplies, CPU’s, switches, UPS, RAM and the clients connecting to it need to have redundant NICs or HBAs and multi-path solutions configured. Even once you have eliminated hardware as a single point of failure, the SAN is still controlled by firmware which itself is a single point of failure. And then because the SAN resides in a single location, any physical disasters (think water, fire, etc.) also represents a risk.

I/O Performance

Given same disk specs, disk installed locally will perform better than disks stored on a SAN accessed via iSCSI. Also, using local storage opens up the possibility of using even higher speed storage solutions such as flash based PCIe storage which outperforms SANs that costs hundreds of thousands of dollars at a fraction of the costs.

Cost

Not only do you have to factor in the initial investment, which the DataKeeper solution wins by a significant percentage, you have to factor in the ongoing expense involved with maintenance, power and cooling required for any enterprise class SAN.

Supports future expansion for Disaster Recovery

Should disaster recovery solutions become a requirement in the future the DataKeeper solution can easily accommodate adding an addition Hyper-V node in a remote location in a multisite cluster configuration for a robust disaster recovery solution that includes the best RTO and RPO available. The SAN solution would require the purchase of an additional SAN, replication software and might not even include cluster integration as there are only a few solutions that actually integrate with failover clustering as well as DataKeeper does.

Eliminates Planned Downtime

With SAN based cluster solutions, any maintenance on the SAN requires planned downtime. The DataKeeper solution allows for rolling upgrades, meaning planned downtime for hardware maintenance is eliminated.

Eases management

SAN administration usually involves a SAN administrator who is familiar with the features and functionality of a SAN. The DataKeeper solution on the other hand is a simple software solution that is managed by the Windows Server administrator and features complete integration with Windows Server Failover Clustering, meaning the management is controlled through failover cluster, a tool which should be familiar with most Windows Administrators.

Summary

In summary, DataKeeper is able to provide a much more resilient cluster solution at a fraction of the cost of SAN based solutions.

SQL Server 2012 Alwayson Multisite Failover Cluster Instance White Paper

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Building SQL Server Multisite Clusters

Here is an excellent white paper on SQL Server Multisite Clusters, however they forget to mention that you can also do this with host based replication. Instead, they assume you have “two EMC Symmetrix VMAX enterprise storage arrays, one at each site. The arrays were both configured with two VMAX storage engines and 240 disk drives”.

How About A More Cost Effective Solution?

If you have a million dollar budget for storage, go ahead and knock yourself out. If not, look into some Fusion-io PCIe Flash storage and host based replication with DataKeeper cluster edition. It is faster than a SAN at a fraction of the cost with all the availability. Check out how Polaris Industries did just this http://www.fusionio.com/blog/polaris-sios/

Reproduced with permission from https://clusteringformeremortals.com/2013/02/05/sql-server-2012-alwayson-multisite-failover-cluster-instance-white-paper/

DataKeeper Cluster Edition for SQL Server High Availability In AWS Cloud

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The potential cost savings of moving to the cloud is nearly impossible not to consider. However, after you stop counting the money you are going to save, you start thinking about things like security and availability and wonder whether the cloud is for you. But fear not, we’ve got just the right solution – SIOS Datakeeper Cluster Edition.

In a traditional data center, you have the control and can deploy whatever security and high availability solution you like. However, once you decide to move your servers to the cloud your choices can become much more limited. It doesn’t matter whether you’re with Amazon, Google or Microsoft, outages in the cloud can and do occur and you need to do whatever you can to mitigate such risks.

Amazon Web Services

Let’s take a closer look at Amazon Web Services (AWS) for instance. What are the options you have to ensure that your SQL Server database can survive an unexpected outage? While some applications can be deployed in a load balanced configuration across multiple availability zones, SQL Server is generally not deployed in a load balanced configuration. What this means is that SQL Server itself resides in a single availability zone and if that zone should become unavailable, your whole application stack can come to a grinding halt.

SQL Server 2008 R2 and its limitations

If you read this article by Miles Ward, you will see that with SQL Server 2008 R2, your availability options are pretty limited. In that article on page 11, there is a nice chart that lays out your HA options. As you will see, the options are severely limited and mostly fall outside of the category which would be described as HA. Log shipping, mirroring and transactional replication are pretty much the only options you have, and they are more of a data protection options rather than HA options. If you want Microsoft failover clustering, you will find yourself out of luck due to some network limitations (clients can’t connect to a clustered IP address) in AWS and the lack of a shared disk resource required for traditional SQL clusters.

AWS

If you are looking to deploy SQL Server 2012, your options get a little better. As described by Jeremy Peschka, with a little manual intervention you can deploy AlwaysOn Availability Groups in AWS to do asynchronous replication from your data center to AWS, or even between AWS availability groups. Of course this assumes you have the SQL 2012 Enterprise license required for AlwaysOn Availability Groups. The only “issue” is that AWS really doesn’t support moving cluster IP address from one server to another, so client redirection has to be done manually using the ec2-unassign-private-ip-addresses and ec2-assign-private-ip-addresses commands after switchover that Peschka describes in his article. All-in-all this is a very manual process, which again does not really fit the description of a highly available system.

A Solution To The Limitations

If you can live without automated recovery and with the limitations of AlwaysOn Availability Groups that I described in a previous blog post, then you might just want to go ahead and try the AlwaysOn Availability Group deployment in AWS. However, if you are looking for an easier, more affordable, more robust HA solution, I have some really good news. SIOS Technology Corp has been looking at this problem and has developed a solution that overcomes all of the limitations previously described and will be available as an AMI for easy deployment. This solution is currently in private beta, but will be widely available later this year.

SIOS DataKeeper Cluster Edition

The SIOS solution is based on SQL server in a Microsoft Failover Clustering using DataKeeper Cluster Edition host based replication. By using hosted based replication they have overcome the first obstacle of clustering in EC2 – lack of shared storage. The second obstacle that SIOS had to overcome was the issue of client redirection described by Peschka; the client access point needs to be manipulated from within EC2, not failover clustering. SIOS has built intelligence into their AMI solution such that the reassigning of the IP address is automated as part of the cluster failover process, effectively simulating the behavior you would normally expect from a cluster.

And because all of this is built on top of failover clustering, this can be deployed using SQL 2008/2008 R2 or 2012. Even the Standard Edition of SQL Server will support a 2-node cluster so the cost savings vs. deploying SQL 2012 AlwaysOn Availability groups could be substantial.

Let me know what you think. Does SIOS Datakeeper Cluster Edition sound interesting? What are you doing today to ensure the availability of your SQL Server EC2 instances?

Reproduced with permission from https://clusteringformeremortals.com/2013/01/11/sql-server-high-availability-in-aws-cloud/