This is my first time here. So, apologies if I get something wrong. I am trying to draw an inter-DC topology for which I want to use a Cisco icon for datacentre. Until now my search has been futile and I haven't found anything useful. So, I want to ask you if an icon for a datacentre exists at all. I would like to use this for my picture. Thanks in advance
Network diagrams typically consist of both a physical topology view and a logical topology view. So, for your physical topology view, use the manufacturer's chassis icons along with rack icons.
For the logical topology, you can use fuzzy wires (for Ethernet), clouds (for like services / subnets), etc.
Data Center's are beginning to use compute/network orchestration systems such as OpenStack which may include SDN (where the virtual networking function such as a vFirewall or vRouter follows a vm when dragged / dropped around the physical boxes) so signifying that in a diagram requires some creativity.
Currently, there is no single icon that depicts a data center. However, there is an abundance of icons depicting elements of a data center. Just to name a few: FC storage; FDDI ring; FC disk subsystem; file server; storage router; storage server. Here you can download them in various formats.
I agree with user2964971's post, but thought I'd also mention Visio Cafe.