As I mentioned in the first blog, you will want to do a test migration to a dev or test environment. This is to ensure that all of the necessary items that have been set in the pre-work are in place. While no migration can be 100% this is a good way to validate as many steps as possible

Testing will allow you to take a sample of the source environment and move it to the target to validate that all of the content types and associated items. It also solidifies your plan of attack.

When I do my test migration regardless of size I use the following format:

• Copy the structure for the top of the site collection, this includes the list, libraries, content types and permissions. This DOES NOT include any of the actual content.
• Validate that all of those items actually made the trip to my target test environment.

Why do I do the top level first? Because all of the sub-sites and content below are in some form or fashion getting the information from the root site collection. All of the site columns and content types are stored at the root. The permissions all live at the root level, it also allows me to clean out all of those old permissions that are left over from users who are no longer with the company and provide a clean place to validate and do a permissions audit.

After the root site has been migrated and any troubleshooting has been completed, I use the next migration to copy the rest of the structure of the site collection and sub-sites. As before you will do all of the information but not include the actual content. Validate it all is in place and move on to the actual migration of the content.

I use a variety of third party tools for my migration efforts, Metavis, Metalogix and ShareGate. There is something for every budget and every need. I will be doing a review of these tools in future blogs but for now the general principal is then same.

Migrate the root site first of all of the content. You know those validation steps we mentioned in the previous blog, this is where you will do them. Remember this is a sample of content you are testing not every single piece of content. I have seen where companies will want a complete mirror environment of production. That is something that can be done now but depending on your schedule and budget is something that can also be done further down the road.

If your test migration has a few glitches that is to be expected, as I said before all environments have their own quirks and you will need to adjust to them as they happen. You may even need to re-migrate content again to ensure you have addressed  the glitches. However, if you have followed all of the steps and done all of the pre-work you are on the road to successful migration.

Migrations take time and are not something that you will want rush, there are a lot of factors to consider when you do them, resources, throttling on the tenant, bandwidth, but mostly it is time consuming but so worth it when it is all moved and in the new environment.

I hope you have enjoyed this series I am sure I will be fine tuning it but keep on checking back for latest information and if you need any help just leave me a comment and I will get back to you.