Last night we had an issue where the permissions were altered a SQL 2008 R2 Cluster Instance, such that the instance could no longer access the shared drives where the system databases were installed. While we corrected it by adding the service accounts to the directories and granted them full control, I would still like to understand the root cause/default setup.
When I perform a cluster install, I can see a grant to the cluster resource drive to an MSSQL$ account/group and that account/group is granted full control of anything in that resource. I don't need to add the service accounts and the cluster works correctly, with the ability to fail over. However, if I add a LUN to that cluster resource (mount point) or if someone goes in and removes that MSSQL$ from one of the cluster resources, I can't add that same account/group and grant it permissions, as Windows will not find it in any of the security objects that can be added.
So can anyone shed light on what this account/group is and is there a way to add it to a folder AFTER a cluster install?
This is SQL 2008 R2 RTM on Windows 2008 R2.