One of the basic building blocks of Azure DevOps Server is a “Project collection”.
The documentation describes it like this:
The primary organizational unit for all data in Azure DevOps Server. Collections determine the resources available to the projects added to them.
From a technical standpoint, a project collection is a separate database. It is possible to move project collection between different database instances but be aware that just backing up a collection on one database server and restoring it on another database server is not sufficient. The well documented way is through a detach/attach operation as I explained last week.
But another ‘hidden’ option exists through an “Offline detach”.
Backup the collection and configuration database
Take a backup of the collection database that you want to move using a tool of your choice and restore it on the database server used by your target Azure DevOps server. Also take a backup of the configuration database and restore it as well(using a different name to avoid overriding the real configuration database).
Convert the database to an attachable collection
The trick is to convert the database to an attachable collection by copying over the configuration data from the configuration database to the collection database.
TfsConfig offlineDetach /configurationDB:DevOpsSQL;Tfs_Configuration /collectionDB:DevOpsSQL;Tfs_ExampleCollection
Attach the collection
Now you can to attach the collection again as with the normal procedure. So back to the Azure DevOps Administration console:
Remark:
Although I tested the approach above and it worked, it isn’t recommended. The collection and configuration database should be perfectly in sync. So preferably only do this when your Azure DevOps instance is offline.