Packet Capture in a ring network

Hi all,

Looking for some advice on how one would go about doing a network traffic analysis on a ringed network.

Essentially I want to capture all network traffic in a 24 hour period for a network. I was going to use wireshark and just capture a pcap file to disk. I'm happy configuring port mirroring on an uplink port which id mirror to an access port and connect my capturing laptop into.

What I'm wondering is, whats the best approach for in a ring network, lets say of 4 switches, each switch has access devices connected and I want to capture all the traffic for the network. Is there an easy way of doing this without having to have a capture device plugged into each switch?

Thanks!