Mark Ziskind, Headwaters Group President and Chief Storage Architect

3PAR Online Import Utility for EVA, EMC CLARiiON

Our group delivers hundreds of data migrations each year. Most involve an older storage array which is being refreshed by a newer, more modern array. The question of how to move the data from point A to point B – or from the legacy array to the new target array – always comes up. Usually, there are at least 2-3 techniques that our team can use given the situation each with their pro’s and con’s.

This series of articles will focus on these various techniques to help you make a better decision about when and where to use a particular technique.

Today, we will discuss the HP 3PAR Online Import Utility. In 2011, HP introduced 3PAR Peer Motion which provides federated storage or what some would call virtualized storage. In late 2012, HP extended Peer Motion to support online migration from HP EVA arrays. Then, in early 2014, HP released the Online Import Utility for EMC VNX and EMC CLARiiON.

The Situation

In this project, our team was responsible for migrating data from an older EMC CLARiiON and an HP EVA to a new 3PAR array. This client had several dozen Physical hosts of various operating systems attached to these legacy arrays, and our team needed to make a decision about which technique to use to migrate the data to the new 3PAR. The usual questions were raised: Which technique would be the simplest? Which would involve downtime? Which would be the least risky? Could we coordinate all the migrations from a single software wizard?

The Headwaters team, our VAR client, and the end-user ultimately decided to go with the 3PAR Online Import Utility for these hosts, and we were pleased with the outcome.

How It Works

First, we’ll cover the migration from the HP EVA.

At a very, very high level, the HP 3PAR Online Import migrates data from an HP EVA P6000 to HP 3PAR system by creating a SAN connection between the source EVA and the destination 3PAR through the use of dedicated ports called Peer Links. Then, the LUNs on the EVA are assigned internal addresses within the 3PAR and called Peer Volumes. Next, the Physical hosts are re-zoned to the 3PAR through the SAN Fabric. Lastly, the migration is orchestrated from within EVA Command View.

Things are slightly different when using the Online Import Utility to move data from the EMC VNX or EMC CLARiion.

To create the Peer links to the EMC, you need to install an additional software tool called the EMC Solutions enabler for SMI-S tool. Think of this is as sort of a proxy or an interpreter that sits between the 3PAR and the EMC to make sure that all the communication that passes speaks a language that both arrays can understand. In the case of the VNX or CLARiiON, the SMI-S tool communicates to the array via IP, but, in the case of the VMAX, the SMI-S tool communicates via Fibre Channel to a dedicated LUN device on the array.

Lastly, with the EMC, the Online Import Utility will live on the same server as the SMI-S connector.  With the EVA, it is operated and contained inside of Command View.

The Gotchas

With the Online Import Utility, you will most certainly hit a few obstacles that you didn’t know about when you planned this out on paper. That comes with the territory, but, hopefully, you can use a few of these points in your planning.

• EVA Command View software Version. The software has to be at a certain version for the 3PAR to be able to communicate with it and for the OIU software wizard to work right. In many of the cases we see with our Clients, the Command View has been working fine and the Storage Administrator has not upgraded or patched it to the latest version. I don’t blame him – it is working well. Consider though, that upgrading may be a multi-step process requiring considerable time and effort to download and apply each required intermediate version. In other words, you can’t just go from 9.3 to the latest version.
• EMC SMI-S Tool. Occasionally, a Client will want to load this tool on an existing server – say, a SAN Management or tools host. But, software may exist on that host that could already be using key TCP/IP ports that the EMC SMI-S tool is configured to use. So, in our view, avoid this right off the bat by using a new, dedicated virtual machine that has no other purpose in life.
• Peer Port Connections to the EMC Array. You need to remember to register your 3PAR initiators on the EMC array and set the correct failover mode (mode 4). Secondly, your fabric zones should be 1-to-1. Meaning, create a 2-member zone that contains 1 3PAR Peer Port and 1 CX4 Port, as opposed to zoning the Peer Port to both SP-A and SP-B.
• Multi-pathing Software. If EMC is your source, your host can’t use PowerPath, and you will need to plan for a switch to MPIO (for Windows).
• CLARiiON / EVA Firmware – Check with HP and make sure your version of the CX4 or EVA firmware is at the right level. If not, adjust your project plan accordingly in your timelines to load the right level prior to attempting any OIU migrations.

How Long Does It Take?

Think of the process as a 2-phased approach.

I’ll call the first phase the pre-migration phase. Here you knock out your pre-migration tasks like un-installing / re-installing the correct multi-pathing software, rezone your hosts, and reboots.

I would suggest you give yourself a window of about 2-3 hours for these things, although you could realistically knock it out in 20-30 minutes.

The second phase is the actual migration that occurs while the host is up and the application is running. (Remember that the server and the applications will be up and running and writing data to the 3PAR while the data migration is going on in the background.) We recently did roughly 1.8TB in about 2 hours – less than 1TB per hour approximately.

On the EMC side, we recently moved 400GB in about 45 minutes. Keep in mind, that some of the EMC documentation suggests that the OIU migrations should be done “offline” so as not to impact array performance.

You can only perform the 1 OIU operation for 1 host at a time. Adjust your project plans accordingly.

Keep in mind also that there are a few clean up tasks once you are done such as reconfiguring the Peer Connections by changing those port attributes back to their original state, un-zoning the source and target ports in your SAN fabrics, and removing the source volumes.

Conclusion

Our 3PAR customers really like this tool, and so do we. I hope this helps you plan your next migration.

About Headwaters Group

Founded in 2005, Headwaters Group, Inc. provides professional services and consulting to IT manufacturers, solutions providers, and enterprise IT organizations. Headwaters’ consultants specialize in the design, deployment and management of complex enterprise storage environments that require a more sophisticated level of engineering talent. For more information on our team and our capabilities, visit www.TheHeadwatersGroup.com