Sometimes when doing deployments to our farm there are errors that appear where the GAC DLL is noted as being in use, this happens even though we stop/start the SP services before uninstalling and installing WSP's. Often times during failure the Worker Process will fail and not start up again, requiring someone to manually go and restart the services. At times we've seen error messages where DLL's are also being held on other machines in the farm.
Has anyone else seen this in deployments? Are there ways to stop/start services from the CA to make sure that no other server in the farm is holding DLL's open?