One of our branch IT staff complained that accessing their group and user data was slow. I logged onto a server in the branch site and tried browsing the data and also found it’s reaction, far from normal, a bit retarded. Browsing folders in explorer would hang explorer from a while before responding.
As our DFS links point to Netapps filers, I thought, it could be a problem with the filer performance. So I opened the physical folders and tried browsing around, but performance was good.
So the issue must be coming from the DFS roots itself, but why would this degrade suddenly?
A quick check on the cache with dfsutils immediately tells me what is wrong, I am getting my referrals from another branch (say from Taiwan to India!). No wonder its slow!
Another check and I found that we had decommissioned a DC in this branch sometimes ago and its a replica of our DFS root. We have a dead DFS root target.
To remove dead DFS root target, you cannot do it from the GUI, you have to use dfsutil to remove the dead target:
dfsutil /unmapftroot /root:\\myroot.com\myshare /server:\\server /share: myshare1
Check out MS DFSUtil examples.