Hi All, Here is my question. We got 3 Ex2010 servers with HT, CAS, MBX roles colocated and DAG inplace. http://blogs.technet.com/b/exchange/archive/2010/07/22/3410475.aspx and http://technet.microsoft.com/en-us/library/ee861125.aspx have the Best practices for installing Excahgne Updates and Rollup when roles are colocated and when u have a DAG server. But in a case of of installing only security updates or some software on the servers how would the procedure go, or is it the same? For example for Server1 On server1 run startdagservermainantace.ps1Drainstop the CAS server on the NLB for Server1.Then do the securty updates.stopdagservermainanace.ps1return CAS to the NLB For the second task - i know that this step is necessary when doing a update of exchange, as we need to have the CAS role always on the same or higher version the the MBX role. But in a case of only applying securty udpates this step is needed so that users wont see any downtime? Am I correct? Thanks Zarko

Same procedure, as there may well be a reboot required and you want o minimise downtime of prod.Sukh

Tnx for confirming.