Adventures In cDOT Migrations: Part Two

By June 1, 2014How To, NetApp

Before we start: for those just joining the adventures, here’s Part One.

Part Two: Insights From The Field

When it comes to 7-Mode to cDOT transitions, we are seeing the trend of host-based migration continuing to be King when it comes to databases and virtual environments. However, for those customers who are using SnapMirror where re-seeding those primary and secondary volume relationships is not an option due to WAN limitations, the 7MTT (7-Mode Transition Tool) is becoming the work horse of our transition engagements.

It’s critical going into this process to understand the capabilities and limitations of the tool. Let’s take a look at some of the technical terms around the 7MTT.

  • A Project is a logical container that allows you to setup and manage the transition of a group of volumes.
  • A Subproject contains all of the configuration data around volume transitions, i.e. SVM mapping, volume mapping and SnapMirror schedule.
  • A Transition Peer Relationship is the authorization management mechanism for the SnapMirror relationships are between 7-Mode and cDOT systems.

One of the limitations around the 7MTT is that twenty volumes can be managed inside a project container. There is typically some planning and strategy around grouping volumes together either by use case or RPO/RTO. The look and feel of the transition is very SnapMirror-like: it follows a baseline, and has incremental and cutover format. There is also a CLI, but using the GUI is the recommended approach.

As with any services engagement, due diligence leads to success and these 7-Mode to cDOT transitions require careful planning and collaboration as they can take weeks to months depending on the size of the environment to complete.

“These 7-Mode to cDOT transitions require careful planning and collaboration as they can take weeks to months”

7-Mode Transition Tool 1.2 Data and Configuration Transition Guide For Transitioning to Clustered Data ONTAP® can be found here with a NOW account login.

Important note: You should be aware of the versions of Data ONTAP operating in 7-Mode that are supported for transitioning to clustered Data ONTAP version 8.2.0 or 8.2.1. You can transition volumes from systems running Data ONTAP 7.3.3 and later. For the updated list of Data ONTAP versions supported for transition by the 7-Mode Transition Tool, see the Interoperability Matrix.

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