SQL Server Standard Edition Archives

Replicating A 2-Node SQL Server 2012/2014 Standard Edition Cluster To A 3rd Server For Disaster Recovery

Disaster recovery for SQL Server Standard Edition is possible with SIOS DataKeeper Cluster Edition. Here’s how.

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 it comes with 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.

Disaster recovery for SQL Server Standard Edition

One of those options is SIOS DataKeeper Cluster Edition. DataKeeper will work with your existing shared storage cluster. The software allows you to extend it to a 3^rd node using either synchronous or asynchronous replication. If you are using SQL Server Enterprise, simply add that 3^rd node as another cluster member for a true multisite cluster. However, since we are talking about SQL Server Standard Edition, you can’t add a 3^rd node directly to the cluster. The good news is DataKeeper will allow you to replicate data to a 3^rd node so your data is protected.

Disaster recovery for SQL Server Standard Edition means you are going to use DataKeeper to bring that 3^rd node online as the source of the mirror. Next use SQL Server Management Studio to mount the databases that are on the replicated volumes. Your clients will also need to be redirected to this 3^rd node. But it is a very cost effective solution with an excellent RPO and reasonable RTO.

The SIOS documentation talks about how to do Disaster recovery for SQL Server Standard Edition. Here, I have summarized the steps recently for one of my clients.

Configuration

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 driver. It’s an important step because you don’t want two servers have 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. As part of that process DataKeeper will ask you about the SECONDARY server which shares the volume you are replicating.

In The Event Of 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. 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). PRIMARY and SECONDARY are a two node shared storage cluster. 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 Disaster Recovery 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 Disaster Recovery 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 some of the possible configurations for disaster recovery for SQL Server Standard Edition. http://videos.us.sios.com/medias/aula05u2fl

Reproduced with permission from Clusteringformeremortals.com

Epicure Selections is using SIOS DataKeeper Cluster Edition software to easily and cost-efficiently provide HA and DR protection for its business-critical SQL Server applications without the complexity of building out a remote DR site or purchasing costly SQL Server Enterprise Edition licenses. SANLess Clustering

Epicure, Canada’s leading direct sales company, sells healthy, easy-to-prepare food products through a network of over 16,000 consultants.

Epicure relies on two websites for its critical business operations. Its public website provides product, company, and consultant enrolment information to customers and people interested in becoming a consultant. The internal website provides consultants with important product information and enables them to place orders.

The company uses two instances of SQL Server Standard Edition—one for each website running on a single server. “Our websites are vital to our business,” said Russell Born, Senior Network Infrastructure Administrator at Epicure.

As the company grew and expanded its products and services, the Epicure IT department needed to update and protect its business-critical websites from downtime. It decided to move both websites from a third-party hosted facility to its on-premises data center and Amazon Web Services. “The business is growing and we needed to ensure our website delivers an excellent user experience for our customers and consultants,” said Born.

As part of this update, Epicure wanted an efficient, cost-effective way to provide high availability and disaster protection for both websites while continuing to run them on two instances of SQL Server Standard Edition. “We didn’t want the added expense of moving to SQL Server Enterprise Edition if we could provide HA and DR with Standard Edition,” Born said.

Using SIOS SANLess clustering software, Epicure IT staff created a two-node cluster in an active-passive failover configuration that enables each SQL instance to failover independently. One cluster node is in the on-premises data center and the second node is in an instance of the AWS EC2 cloud. Epicure IT staff created the SIOS SANLess clusters and configured them using the software’s intuitive graphical user interface.

The SIOS software provides Epicure with an easy, cost-efficient way to provide HA and DR protection for its business-critical SQL Server applications without the complexity of building out a remote DR site or purchasing costly SQL Server Enterprise Edition licenses. “The SIOS software has allowed us to create a hybrid solution providing additional cost savings of running on-premises with the reliability and flexibility of running in the cloud,” said Born. “Knowing that a website outage will result in an automatic failover allows our IT Team to focus their attention on other priorities to strengthen our business.”

About the Author:

Jerry Melnick
COO, SIOS Technology Corp.

Jerry Melnick (jmelnick@us.sios.com) is responsible for defining corporate strategy and operations at SIOS Technology Corp., maker of SIOS SAN and #SANLess cluster software. He more than 25 years of experience in the enterprise and high availability software industries. He holds a Bachelor of Science degree from Beloit College with graduate work in Computer Engineering and Computer Science at Boston University.