I have 4 C9500-48Y4C switches in two different locations. I am using the stackwise cable to stack two switches in each location but can I use Fiber connections to join the two locations to make one logical core using the four switches. Thanks in advance.
Yes it is possible to create a virtual stack.
Under this link you can look it up:
according to IOS XE 16.9 documentation
Cisco StackWise Virtual is supported only on the following models:
Your model is not listed you should look also at latest 16.11 for security in any case you can only join two switches in an SVL pair.
according to the following whitepaper provided by Balaaj in another thread
on IOS XE 16.10.1 support for model C9500-48Y4C has been added see on pag 9 of the above whitepaper.
So with appropriate IOS XE version you can build two SVL pairs and interconnect them with fiber links.
Hope to help
if you refer to stackwise virtual it is limited to only two switches
Cisco StackWise Virtual is a network system virtualization technology that pairs two switches into one virtual switch. Switches in a Cisco StackWise Virtual solution increase operational efficiency by using single control and management plane, scale system bandwidth with distributed forwarding plane, and assist in building resilient networks using the recommended network design. Cisco StackWise Virtual allows two physical switches to operate as a single logical virtual switch using a 40G or 10G Ethernet connection.
So in your case you will have to peer between two SVL pairs
in simple words read SVL = VSS in C6500/C6800 or C4500X
Hope to help