Just a few weeks ago I wrote an article about how to configure the iSCSI Software Target 3.3 in a cluster environment. While it is great for labs and testing, up until today it was not supported in a production environment. Well…that all changes today! Microsoft just announced that the iSCSI Software Target 3.3 is a freely available download and can be used on a production network.
This all starts to get interesting once you start considering the possibility of building shared nothing iSCSI Target clusters with DataKeeper Cluster Edition. Build 2-nodes locally for HA and then place a 3rd one in a remote data center for disaster recovery. Now that is a pretty sweet HA/DR solution without having to break the bank!
I am very happy to announce that I have been elected Microsoft Most Valuable Professional (MVP) in Clustering for a second year in a row. It is a great honor and I certainly enjoy the benefits of being recognized as an MVP, including free dinners and drinks wherever I go! Well, OK, that is just my imagination getting the better of me but I did enjoy the MVP Summit and meeting lots of really smart people. In addition to being elected MVP I had the best day ever on my blog, until I discovered that WordPress played an April fool’s day joke on me! I thought that my being elected MVP must have been the headline on CNN or something. They really got me good!
There are some reports on the newsgroups of storage validation failures after upgrading 3+ node clusters to Windows Server 2008 R2 SP1. It seems Microsoft is aware of the issue and they are investigating. I have been following this thread to keep up to date on the issue
You might want to wait for some sort of resolution before you apply SP1 to your clusters.
Now that Starwind has stopped offering a free, limited version of their iSCSI target software you might be looking for an alternative for your labs. Microsoft has recently made their iSCSI target software available as part of the Windows Storage Server 2008 R2 download on Tech-Net and MSDN. It is not for use in production and has some of its own licensing restrictions, but it works fine and it is free for Tech-Net and MSDN subscribers.
I recorded some really quick and dirty videos that aim to show you how to configure the iSCSI target and iSCSI initiator software in under 7 minutes. At the end, you will have a shared disk array ready to start your shared storage cluster. Hopefully when I get some more time I’ll actually write these steps out, but in a pinch this will give you the general idea of what needs to be done. There are plenty of other features, but for a lab environment this will do the trick.
http://screencast.com/t/2qUUDvZo6Zka – configuring the iSCSI target software and iSCSI initiator on the client
http://screencast.com/t/7m9ElSIdAbP – configuring the iSCSI initiator….continued
The stats helper monkeys at WordPress.com mulled over how this blog did in 2010, and here’s a high level summary of its overall blog health:
The Blog-Health-o-Meter™ reads Wow.
About 3 million people visit the Taj Mahal every year. This blog was viewed about 54,000 times in 2010. If it were the Taj Mahal, it would take about 7 days for that many people to see it.
In 2010, there were 13 new posts, growing the total archive of this blog to 30 posts. There was 1 picture uploaded, taking a total of 2kb.
The busiest day of the year was August 18th with 347 views. The most popular post that day was Step-by-Step: Configuring a 2-node multi-site cluster on Windows Server 2008 R2 – Part 3.
Where did they come from?
The top referring sites in 2010 were social.technet.microsoft.com, social.msdn.microsoft.com, google.com, google.co.in, and ditii.com.
Some visitors came searching, mostly for sql 2008 r2 cluster step by step, clustering for mere mortals, there was an error setting private property ‘requirekerberos’ to value ‘1’ for resource ‘sql network name, and hyper-v r2 sizing.
Attractions in 2010
These are the posts and pages that got the most views in 2010.
Step-by-Step: Configuring a 2-node multi-site cluster on Windows Server 2008 R2 – Part 3 October 2009
13 comments and 1 Like on WordPress.com,
Step-by-Step: Configuring a 2-node multi-site cluster on Windows Server 2008 R2 – Part 1 September 2009
14 comments and 1 Like on WordPress.com,
Step-by-Step: Configuring a 2-node multi-site cluster on Windows Server 2008 R2 – Part 2 September 2009
Making sense of virtualization availability options August 2009
Microsoft’s latest version of SQL, code named Denali, is currently in CTP. One of the most anticipated feature is something called HADRON. Basically, it is has been described as mirroring 2.0. The best features of HADRON as I can see compared to mirroring as it is in 2005/2008 are as follows:
- You can query the mirror (now known as a replica)
- You can have more than one replica
- Database are grouped into availability groups to ensure related databases always fail over together
- Support for replicating more than 10 databases
If you want a great preview, check out fellow MVP Brent Ozar’s post, SQL Server Denali Rocks!
From reading Brent’s post I gather Microsoft only plans to include this in the Enterprise version of SQL. That is too bad for the many customers running SQL Server Standard as traditionally there is a significant price jump to go from Standard to Enterprise. However, that is good news for the 3rd party replication vendors out there who are providing similar functionality today on SQL 2005/2008 on Standard and Enterprise Editions.
While it is not an exact duplicate of HADRON, a multisite cluster using SteelEye DataKeeper Cluster Edition for SQL Server gives you a great solution for HA/DR without requiring shared storage. So while we wait for Denali and all the application vendors to start supporting Denali you might want to have a look at what SteelEye DataKeeper Cluster Edition can do for you today!
It seems as if there could be a vulnerability which would allow unauthorized access to administrative shares! You will certainly want this patch ASAP and also don’t forget to check the permission levels on your administrative shares after you apply this patch.
Recommendation. Microsoft recommends that customers consider applying the security update using update management software, or by checking for updates using the Microsoft Update service. Additionally, after applying the update, customers should check the permissions on existing cluster disk administrative shares and set the proper access levels for their environment.
If you are at Tech-Ed in New Orleans this week make sure you stop by the Windows Server Failover Cluster booth in the Technology Learning Center and have a look at the multi-site Hyper-V cluster demo using SteelEye DataKeeper Cluster Edition as the replication engine. I’ll also be in the booth to answer any questions you may have. SteelEye also has a booth at the show if you would like to discuss becoming a partner or customer!
I answer this question often enough that I thought I should probably but a link to it in my blog.
This article tells you everything you need to know. However, what you may not realize is that by following the instructions in the article you are minimizing the amount of planned downtime while also giving yourself the opportunity to “test” the update on one node before your upgrade both nodes. If the upgrade does not go well on the first node, at least the application is still running on the second node until you can figure out what went wrong.
This is just one of the side benefits that you get when you cluster at the application layer vs. clustering at the hypervisor layer. If this were simply a VM in an availability group, you would have to schedule downtime to complete the application upgrade and hope that it all went well as the only failback is to restore the VM from backup. As I discussed in earlier articles, there is a benefit to clustering at the hypervisor level, but you have to understand what you are giving up as well.