vTiger CRM 6：本地设置适用于/ var / www但不适用于不同的分区。 为什么？

I have first got cloneed vtiger at different partition which is mounted at /data/and checked out to 6.5.0

Installed php5.6 and necessary plugins(don't suggest installing php7.x I cannot) from ondrej launchpad.

Created a VHost in apache2/site-enabled/crm.conf

<VirtualHost *:80>
    ServerName "vtiger-local.host.com"
    DocumentRoot "/data/CRM/"
<Directory "/data/CRM/">
   Options Indexes FollowSymLinks Includes ExecCGI MultiViews
   AllowOverride None
   Require all granted
</Directory>
</VirtualHost>

Edited /etc/hosts file

127.0.0.1 vtiger-local.host.com

After that I did a chmod -R 777 but It is throwing

Call to a member function Execute() on null in /data/CRM/vtigercrm/include/database/PearDatabase.php

But same exact configuration is running smoothly when I git clone at /var/www

Anything I am missing?

P.S Edited $root_directory as well as $site_URL Forgot to add with the original question.

Just copied the folder and changed the root path and it started working.

Did you change the path in the config.inc.php folder?

Open the config.inc.php file from the root directory of your CRM. And update the $site_URL parameter with the CRM URL and $root_directory parameter with the root directory path of CRM.