Since the publication of this article, Sharegate has updated and unified the migration interface of its Desktop Tool. The following screenshots may no longer be accurate, we are working on updating them.
Does Sharegate migrate SharePoint permissions?
The answer is yes, but let’s take a moment to explore how it works so you can master the permission migrations.
Permissions in SharePoint are essentially based on three elements: users, groups and permission levels. As if this was not enough, there are also site permissions, list permissions, folder permissions and item permissions.
The key thing to remember is that permissions are linked to objects, therefore in most cases you will need to migrate your structure in order to have your permissions copied over. Migrating a group or a permission level will simply make it available at the destination, it will not update the permissions on all the objects in your sites.
How to migrate SharePoint permissions
Let's go over a few examples to get a better understanding of SharePoint permissions.
Company ABC is a conglomerate with a parent company and multiple subsidiaries. I am in charge of migrating the human resources site that is a subsite of the latest acquisition of Company ABC. In sum, what I need to do is fairly simple. I have to migrate a subsite (HR) that is under the top level site (XYZ.co) to a newly created SharePoint Site Collection, however the HR subsite has unique Site permissions that I would like to preserve.
Here is how to proceed:
Migrate over the groups so that they are all present at the destination with their members. This will ensure that the groups are copied to the root site of the site collection (where all the groups reside).
Then, migrate the HR subsite to the target site with the custom permissions option checked. The custom permissions option allows me to choose if I want to preserve the unique permissions from the source or if I want to go with what I have at the destination (inherit the permissions from the parent)
Remember, the actual permissions migration will take place when the objects are moved (when the site is migrated). The groups copy is only to ensure that all the groups are available and up-to-date prior to the objects migration.
Let's do an example
My boss at Company ABC decided to change my assignment at the last minute. Instead of migrating HR he wants me to migrate only the Blog subsite to our Transport Division Site Collection. The blog subsite inherits permissions from HR.
In that case, the process is also very simple,
Connect to both site collections
Copy the Blog subsite.
Once the migration is done, for some reason, all the Company ABC users have access to the Blog subsite even though they did not have access to it at the source…
In fact, this is normal since I have not migrated the actual site that had unique permissions but only its subsite that inherited the permissions from its parent. Sharegate’s behavior in this case is to simply let the site inherit its permissions from its parent, as it did at the source. Since the new parent site at my destination does not have the same permissions as the old parent site, the subsite now has different permissions.
If I want to change this, I can either break the permission inheritance of the source site in order to have unique permissions prior to the copy, or I can define the permissions at the destination after the copy so that only the desired users have access to the blog.
I could also have migrated the parent site (HR) with its subsite (Blog) to ensure that the permissions are correctly set-up at the destination (the HR permissions would have been copied and the Blog would inherit from them).
What to do when it's over
Once everything is set and done, I might take a look at the actual permissions section of my site, subsite or list that I have migrated so I can compare it to the source. What if I don’t see the Limited Access permission levels besides a user or a group? Well, I certainly don’t need to worry because these are automatically handled by SharePoint and they will only be added if necessary.
For example, if you give a user access to documents within a library and he doesn’t have access to the library itself, SharePoint automatically grants him Limited Access on the library, and also the site, if needed.
Finally, Sharegate enables you to migrate your permissions easily. The custom permissions copy option is key to getting them copied over. It allows you to migrate the permissions whether they are related to Site, subsite, list, library and even items or documents. The only thing to remember is that in order to bring over permissions, you need to copy the object that actually has unique permissions, not only its children that inherit from it.