Hi, I got a joomla site with virtuemart, but because of some reason (site configuration or module conflicts), it got 500 internal server error when browse the VM pages. We installed another copy fresh joomla + VM in a sub-directory, both of them work without problem. However, in this way the two sites need database synchronization. So we are wondering if JMS is a better solution, i.e., create a slave site using JMS, install VM on it, and direct users from the existing site (the master site) to go to the slave site to use VM while sharing users data (CB and alphauserpoints) between the two sites.

However, I just found that, in order to install VM on the slave site, it must be installed on the master site at first. Obviously, if we use the existing site as the master, the VM installed on it does not work well on the master site. In this case, when install a fresh VM on the slave site, can the VM on the slave site function normally?

If the answer for the above question is no, does it work in this structure: Master site(a new site as library for joomla files) + slave site 1 (existing site) + slave site 2 (with VM)? Can user data (CB and alphauserpoints) be shared between the two slave sites?

Please help me make the purchase decision.

Best

Internal Server Error is something that may happen when you have suPHP installed and that you have provide too higher permission on some directories.
Some hosting environment configuration reject directories with 777 and return an Internal Server Error. This is for you security.

Perhpas that when you installl a standalone website in a subdirectory, this does not have conflict because the permission of this subdirectory set is correct.

If you have a problem of permission on some files present in your "future" master website, it is probable that you will also get an "Internal Server Error" as the permission will be the one of your master (an not the one of the subdirectory).

You can try but I am not convinced that your "Internal Server Error" will disappear when converting you current website in a master to build the second one.