6/21/2016 – Update, since I posted this article I have been told by a reliable source that there is a newer PowerShell script that does the job even more reliably. I haven’t tried it yet, but I trust the source and Microsoft Premiere Support directed him to this article. https://gallery.technet.microsoft.com/Azure-RM-Availability-Set-39e19d01
I was a little surprised to find out today that it is not easy to change what Availability Set a VM resides in once it is already created. The Azure portal has no mechanism of adding an existing VM to an Availability Set once the VM has already been created. Fortunately for me I stumbled upon this great resource.
Set Azure Resource Manager VM AvailabilitySet
By leveraging the PowerShell script available for download in that article I was able to add two existing VMs to an Availability Set that I had already created. What a life saver!
I’m usually writing about Windows clusters, but I know there are quite a few people running Linux to support things like Oracle and MySQL. When moving those workloads to Azure and you want to make sure you plan for high availability. Fortunately my colleague Tony Tomarchio over at www.LinuxClustering.net is an expert in Linux High Availability and has published a great step-by-step guide to Linux failover clusters in Azure.
Many people have found themselves settling for SQL Server Standard Edition due to the cost of SQL Server Enterprise Edition. SQL Server Standard Edition has many of the same features, but has a few limitations. One limitation is that it does not support AlwaysOn Availability Groups. Also, it only supports two nodes in a cluster. With Database Mirroring being deprecated and only supporting synchronous replication in Standard Edition, you really have limited disaster recovery options.
One of those options is SIOS DataKeeper Cluster Edition. DataKeeper will work with your existing shared storage cluster and allow you to extend it to a 3rd node using either synchronous or asynchronous replication. If you are using SQL Server Enterprise you can simply add that 3rd node as another cluster member and you have a true multisite cluster. However, since we are talking about SQL Server Standard Edition you can’t add a 3rd node directly to the cluster. The good news is that DataKeeper will allow you to replicate data to a 3rd node so your data is protected.
Recovery in the event of a disaster simply means you are going to use DataKeeper to bring that 3rd node online as the source of the mirror and then use SQL Server Management Studio to mount the databases that are on the replicated volumes. You clients will also need to be redirected to this 3rd node, but it is a very cost effective solution with an excellent RPO and reasonable RTO.
The SIOS documentation talks about how to do this, but I have summarized the steps recently for one of my clients.
- Stop the SQL Resource
- Remove the Physical Disk Resource From The SQL Cluster Resource
- Remove the Physical Disk from Available Storage
- Online Physical Disk on SECONDARY server, add the drive letter (if not there)
- Run emcmd . setconfiguration <drive letter> 256
and Reboot Secondary Server. This will cause the SECONDARY server to block access to the E drive which is important because you don’t want two servers having access to the E drive at the same time if you can avoid it.
- Online the disk on PRIMARY server
- Add the Drive letter if needed
- Create a DataKeeper Mirror from Primary to DR
You may have to wait a minute for the E drive to appear available in the DataKeeper Server Overview Report on all the servers before you can create the mirror properly. If done properly you will create a mirror from PRIMARY to DR and as part of that process DataKeeper will ask you about the SECONDARY server which shares the volume you are replicating.
In the event of a disaster….
On DR Node
- Run EMCMD . switchovervolume <drive letter>
- The first time make sure the SQL Service account has read/write access to all data and log files. You WILL have to explicitly grant this access the very first time you try to mount the databases.
- Use SQL Management Studio to mount the databases
- Redirect all clients to the server in the DR site, or better yet have the applications that reside in the DR site pre-configured to point to the SQL Server instance in the DR site.
After disaster is over
- Power the servers (PRIMAY, SECONDARY) in the main site back on
- Wait for mirror to reach mirroring state
- Determine which node was previous source (run PowerShell as an administrator)
get-clusterresource -Name “<DataKeeper Volume Resource name>” | get-clusterparameter
- Make sure no DataKeeper Volume Resources are online in the cluster
- Start the DataKeeper GUI on one cluster node. Resolve any split brain conditions (most likely there are none) ensuring the DR node is selected as the source during any split-brain recovery procedures
- On the node that was reported as the previous source run EMCMD . switchovervolume <drive letter>
- Bring SQL Server online in Failover Cluster Manager
The above steps assume you have SIOS DataKeeper Cluster Edition installed on all three servers (PRIMARY, SECONDARY, DR) and that PRIMARY and SECONDARY are a two node shared storage cluster and you are replicating data to DR which is just a standalone SQL Server instance (not part of the cluster) with just local attached storage. The DR Server will have a volume(s) that is the same size and drive letter as the shared cluster volume(s). This works rather well and will even let you replicate to a target that is in the cloud if you don’t have your own DR site configured.
You can also build the same configuration using all replicated storage if you want to eliminate the SAN completely.
Here is a nice short video that illustrates the some of the possible configurations. http://videos.us.sios.com/medias/aula05u2fl
Today I had to help a customer trying to deploy some VMs in Azure Classic that have two NIC cards. No problem I say, it’s been a while since I worked with Azure Classic but from what I recall it was pretty straight forward, but had to be done via PowerShell as there is not GUI option in the portal for deploying two NICs.
The basic directions can be found here.
However, after banging my head against the wall for a few hours I stumble across this nugget of information.
It seems like what the Azure Portal GUI says the name of your virtual network is can sometime be completely different than the actual name which is returned when you run Get-AzureVMNetSite | Select Name. As you can see in the screen shots below the Virtual Network that I created called “Public-Azure-East” is actually called “Group Group Azure Public East”. How that happened and why the GUI displays the wrong name is beyond my comprehension.
As you can see, my feeble attempts at creating the virtual machine failed, saying “BadRequest: The virtual network Public-Azure-East does not exist.” I was sure it had something to do with the multiple subscriptions I use, but it turned out to be this bug where the Azure Portal Displays the name I used in creating the Virtual Network, however the actual name is something completely different.
Why something so simple as creating a VM with two NICs can’t be accomplished via the GUI is another story completely.
For those of you who still use IE 11 from time to time, you may have noticed that with a recent update your default search provider may have been changed to Bing. Microsoft has made a security enhancement that stops malicious software from hijacking your browser by changing the default search engine and home page. Being the dad of two teenage “gamers” who are always on the verge of downloading the latest malware I do appreciate the added security. However, one of the side “benefits” of this security update is that the default search provider is now Bing and how to change it back to Google in not 100% obvious. Microsoft posts the steps in their article here: http://windows.microsoft.com/en-us/windows-10/internet-explorer-11-settings-protection
As much as I love Microsoft products I just never find Bing very friendly for the types of searching I do which is generally looking for some very specific technical content. I think Bing might be consumer friendly, but Google wins the search engine wars in finding the content I am looking for quickly.
To change the default search engine provider back to Google, just follow the steps in the article. The screen shots below show the steps.
If you were at my session at SQL Saturday Nashville you may be looking for the scripts I used in my session. You can download them here…
I deal with users every week that are moving business critical workloads to Azure. The first question I usually ask is whether they are using Azure Service Management (Classic) or Azure Resource Manager (ARM). I usually recommend ARM as it is the new way of doing things and all the new features are being developed for ARM. However, there are a few things that are not compatible with ARM yet. As time goes by this list of unsupported features gets smaller and smaller, but it is good to know there is an existing document which seems to be updated on a regular basis which lists all of the features and whether they are supported with ARM. https://azure.microsoft.com/en-us/documentation/articles/resource-manager-supported-services/
Although this is a good list, I would say it is not complete. I could not find any indication on that App Service Environment was not supported on this page. I only found that out on the App Service Environment page.
If you have any other roadblocks with using ARM for your Azure deployment comment on this article so we all know what to expect in our deployments.