Security Identifier (SID) History is a useful mechanism in Active Directory (AD) migrations. It allows users and groups in a new domain to retain access to resources that still rely on permissions from the old domain. However, once migrations are completed, these historical SIDs can become clutter, posing both security and administrative challenges. While it’s best to remove unnecessary SID History as soon as you’re done migrating, many environments skip this step. Over time, decommissioned or broken trusts make cleanup more difficult, and domain objects can accrue so many old entries that you lose track of what is still required.
As we work for our customers, we often find ourselves in a position where we know it's not only our problem but most likely, a lot of people will hit this sooner or later. This Technical Hub provides our customers and us with solutions, scripts, and other information useful for Administrators and, to some degree, for non-technical people.