Forensic Image of Server

Does anyone have any recommendations into how to obtain a forensic image of a server? Server in question is a Citrix Netscaler.

I have a attempted a simple ethernet from laptop to server in the hope the laptop would see the network connection and i would be able to obtain a logical evidence file.

I have little experience in this area, so any help & advice / guidance on how to go about this would be appreciated.

Thanks