I’ve been writing about troubleshooting issues for a while now and one of the things that is very difficult and most time consuming is correlating events between host systems, switches and storage arrays in the even of storage related errors. My advice has always been the same. Hook everything up to NTP systems, make sure that time and date settings, including time-zones and DST settings do fall within the drift values of the NTP client and that little nifty piece of software will make sure time is equal on all systems. (See below how to accomplish this.)
There are however some issues when this is not fully followed through and virtual switches are used.