Complexity Among the Switches
Another major challenge facing storage customers is the sheer complexity of today’s SANs. For example, says Ross, if SAN islands are made up of mid-range switches, which are typically of the 16- or 32-port variety, merging them into a large SAN means that you have to consume many ports just to provide inter-switch connectivity. And there are practical limits to the number of hops and domains.
“Exceeding the domain and hop count can result in fabric timeouts, which will affect performance,” says Ross. He believes the best way to build large SANs is to use large SAN switches, usually referred to as director-class switches. “These devices offer high port capacity, which helps keep domain count low and, at the same time, offers a high degree of availability through the use of redundant sub-systems such as power, cooling, and control processors.”
This is Part I of a two-part article on True Integration: Fact or Fiction. Part II of the article will cover the following: