How to recover Pipelines (builds) in Azure DevOps Server 2020 that got removed during install?
Before upgrade: ADS 20219 After upgrade: ADS 2020 (missing build history for 30+ day builds)
The ADS 2020 install will silently REMOVE any builds (pipelines) that are over 30 days old when you install the update from ADS 2019.
Is there a way to RECOVER these other than restoring the database and reinstalling again?
There REALLY SHOULD be a WARNING on this install if MS is going to SILENTLY DELETE MONTHS of build history (data).
From what I can tell, once the cleanup job runs and trauncates the data, your only way to get it back is to revert to pre-upgrade databasses, run the commands to turn off the new retention model outlined in the blog post and perform a new upgrade.
In case you detected these issues way past your migration date, you'd have to replay any changes made in source control and have people verify all the work items they edited in the meantime.