CQ.5.x to AEM6.x migrations with MSM content



Has anyone here run a CQ.5 to AEM6.x migration with MSM content before?

We have a site on CQ5.5 We plan to migrate the site to a fresh AEM6.1 (new servers). It is a simple with no custom Java code, and as such plan to migrate was to take packages from the CQ5.5 instance and install on the AEM6.1 instance via package manger. While this seemed to work in most instances we hit a problem with the Multi-Site Management (MSM) feature.

The existing site uses MSM. The site has been running for years and on this site there are many Livecopy pages that overtime have been deleted and excluded/skipped from further rollouts.  The node structure for Livecopies has changed between CQ5.x and AEM6.x. On AEM6.x the meta-data regarding previously deleted subpages from a Livecopy is stored in the cq:excludedPaths property. This property does not exist on CQ5.x and it is not obvious to me where CQ5.x stores this meta-data (though clearly it must).

Once the content has been migrate one can add (using a Mixin) the property cq:excludedPaths to the LIvecopies migrated to AEM6.1, however we'd have lost any historic data about pre-migration deleted page and as such the rollout action will default to "Create" (on the assumption that this is the first time we roll this out) rather than default to the action "No Action" as it does on CQ5.5 or just not show it in the dialog (as per the AEM6.1 behaviours for pages with Skipped status).

I'm thinking that we could try running the migration in two steps, first we run a AEM6.1 upgrade in-place to correct the structure of the MSM nodes and then create packages of that content on the upgraded instance and deploy them on the new target AEM6.1 instance. Has anyone tried this?