[support] Drupal 7 multi site problem

[Roger]

<snip>
"Multisite" means multiple sites installed on a single codebase. You 
have to have a base installation and that is where the VirtualHost will 
point. ? Nancy
</snip>

Thank you Nancy
The fault was not the base installation but the way I named the test 
multi site.
example.com did not work, apparently because there is a web page on a 
domain called example.com but example1.ab and example2.xy did work well 
as a multi site on my home pc.
It is a bit misleading in the Drupal.org tutorial which uses example.com 
in a number of places as examples for multi site installation.

So now it works on my home Fedora 16 box but I have no luck getting it 
to work on the ISP's remote centos shared server where I cannot access 
nor change httpd.conf, and /etc/hosts does not exist.
Increasingly I find it a pity that apache has to be altered when the 
redirection and access could instead be through /sites.php which in this 
case seems to have no effect, or I am not understanding the instructions.

That sites.php in the /sites folder seems correct but Drupal seems to 
ignore it no matter what I put on the last line as per instructions.
Whatever! It seems that http.conf and /etc/hosts has to be altered and I 
cannot find out how in cpanel or ssh on a shared server.

I wonder how others in similar situations have achieved multi sites on 
shared server?
thanks
Roger