Top Three Things to Know Before You Migrate to Clustered Data ONTAP

By Jeevan John
7/23/2013

Although many NetApp customers might understand the significance of the word “migrate” in the title of this blog, to many it may still be a surprise. Yes, moving from the traditional NetApp 7-mode to the newer clustered Data ONTAP requires a data migration, unlike seamless upgrades that customers are used to with the previous versions. This time around, it requires a complete data migration just as you would be migrating to a heterogeneous storage array. With NetApp being a unified storage platform that supports both NAS and Block protocols, migration to Clustered Data ONTAP requires special considerations for both types of data. As the Data Migration practice manager at Datalink, I have seen first-hand the complexities inherent in migrating to NetApp clustered Data ONTAP, or cDOT, as it is now being called in technical circles. There are a lot of questions that have come up concerning the need to migrate to cDOT, what to migrate and exactly how to do it. So I thought I'd set the record straight and offer my thoughts on the top three things to consider for a cDOT migration.

1. The Why… Considerations for Migrating to cDOT

Why should you be migrating to cDOT? The following four are good reasons to consider for migrating

i. Scalability – With cDOT you can scale performance, capacity and thus business operations while maintaining no disruptions to the business application. to cDOT at the right time for your environment.

ii. Availability - No more downtime is the promise from NetApp. With cDOT you get the ability to seamlessly move data across multiple nodes of the cluster thus ensuring that there is no downtime during software/firmware upgrades, break fix or hardware replacement.

iii. Performance – NetApp has reported unparalleled performance of up to 1.5 million IOPs with multiple nodes of a cDOT cluster. As of today a cDOT system can scale up to 24 nodes. This is a drastic change from the 2 node systems that customers are used to running applications on with the traditional Data ONTAP systems.

iv. R&D and Innovation – It has been made clear by NetApp that most of R&D and future developments will focus on the cDOT code base even though the traditional 7-mode code will still be supported for many years to come.

Now that you know the reasons behind the hype, do you know if clustered Data ONTAP is right for your business? I’ll leave it up to you to decide when the best time to migrate is – you can also discuss this with your technology partner to make this decision.

2. The What…

It is important to understand what is being migrated, not just in bits and bytes but all the way into how this data maps into applications and have an impact on the business. This is critical to ensure that IT can fulfill the SLAs to the business during this transition. Most organizations have some idea of what their applications are dependent on other applications, but in cases where a more detailed analysis is required, performing a detailed application mapping will go a long way in understanding ahead of time, a good picture of the landscape before venturing into the actual migration. NetApp being a unified platform, it is important to know the dependencies from a file as well as block data perspective.

i. Files – It is important to understand the types of files, the storage capacity of these files as well as how many files are there under each folder structure. In addition to this, it helps to know ahead of time how users and applications are accessing this data. This is important to ensure that migration happens smoothly and that the access to the data for users and application is seamless after the migration is complete.

ii. Block data – Block data is typically application based data (LUNs), and by nature migrating block data has inherent complexity because of the nature of how it serves the various applications – so it is important to migrate data from an application perspective rather than from a storage perspective.

3. The How…

The last big item to think about is how the data will be migrated. There are umpteen numbers of methods to move the data successfully and this is different for every environment and every application.

i. There are tools provided by the application vendor (Oracle, Microsoft etc.)
ii. There are tools provided by NetApp to migrate to cDOT
iii. There are third party software and hardware appliance based tools to complete this transformation.

No matter which mix of technology is used for the migration to cDOT, what is important to understand is that this migration is a gradual process, not an overnight change. Following best practices during the migration, as well as ensuring that best practices are followed while implementing the cDOT systems is critical. What we have seen at Datalink is that along with the technologies used for migration, the people involved with the migration also play a huge part – communication is critical. I cannot emphasize enough the importance of project management, establishing clear lines of communication,  and decision making during the migration process.

Whether you have decided that cDOT is the way to go or are in the early stages of contemplating the move to cDOT, consider these recommendations in order to make the migration a success -- with the least amount of disruption possible to the business. And when in doubt, seek an experienced data migration partner who understands not only the technical intricacies of performing a clustered Data ONTAP migration, but also one who can lower your risk and understands the importance of data availability for your business.

Datalink has architected and implemented numerous cDOT migrations. We have a very strong NetApp-focused engineering team and are one of the first partners to develop a formal methodology to migrate to cDOT. Have a question about cDOT? Thinking about migrating to cDOT? Email me -jjohn@datalink.com. I'd be happy to answer any questions you may have.