New to SEO and robots

robots.txt for multiple sites on one server

[dabrisz]

If my directory structure is

site1 dir 1
site1 dir 2
site2
site1 dir 3
site3
ect.

Can I have a robots.txt for each site and should the site1 robots.txt disallow the other sites' directories? Or do I have to reorganize my directory structure?

[volatilegx]

you need a separate robots.txt for each "home" directory. The robots.txt shouldn't reference the other sites at all.