I installed the splunkforwarder on one Linux machine can I copy the /OPT/splunk folder to other Linux machines and do restart of splunk service from bin OR should I install the forwarder fresh on every individual machine.
You could do this, but it could lead to problems later with certs.. I would recommend doing a quiet install on the server and automate it across all your servers that you need Splunk installed on then use the deployment server to configure it
This would work depending on if the arch and build of the machines are the same or near identical. However, your going to have GUID and certs that are identical across your systems. It's better to script and unattended install rather then just copy the directory.