I am using VPS server with CentOS, I installed OpenERP application i created multiple instance for each openerp application by creating different database.

I created 4-5 openerp instance by creating different switch users in centOS. All instance was working smooth but suddenly all went wrong and stoped working and getting message like Oops! Google Chrome could not connect. And if i create a new instance it is work. 

To create multiple instance by refering this link http://saurabhjpd.blogspot.in/ 

Is there any other method to create multiple instance or can we make some correction in this?

Thanks in advance.