I handle servers for numerous clients running multiple sites and versions of Drupal in VHosts on the same server and it works fine. The only thing to keep in mind with memcache is that it is shared, so it's best to actually start a different memcache instance per site, just using different ports. You can prefix memcache in settings.php, but the problem there is that a cache clear will clear everything, just not the prefixes.
If your running PHP5.5+, then instead of using XCache, I would use the Zend Optimizer that ships with PHP5.5+. Performance wise, it's even better than XCache. Generally my go to stack is Nginx + PHP w/APC (Zend if running 5.5+) + Memcached. WIth that on one client's site, which sees over 60,000 pv/hour at peak and over 70 modules (plus being very views and panels heavy), even as user 1 I still get load times around 300ms.
Jamie Holly http://hollyit.net
On 1/10/2015 11:56 PM, Keith Smith wrote:
Hi,
Thank you so much for all your feedback.
I am planning on running 4 small Drupal websites on a Dell i5 that has 4 cores / 4 threads / 8G RAM. This is for learning mostly. The server is in my home office.
I recently used memcached and xcache to take a Drupal site for one minute page loads to 1 second page loads on a 2 core / 4G RAM VPS. Very impressive.
I was wondering if I can use these same techniques on a box that has 4 Drupal virtual hosts on it.
Any thoughts? Will I be caching one site to only have to start over when another site gets some traffic?
Thanks