Migration from one domain to other domain
More than likely, you have a redirect base directive in your .htaccess. This is used when serving your Drupal site out of a subfolder of your webhosting provider's webroot. You should check your .htaccess file for the directive RewriteBase /abc and replace with RewriteBase /xyz
If that still doesn't work, check the vhost entry of your webserver for the same directive.  
Otherwise, if the site still redirects to "/abc", then you may have a $base_url defined in settings.php causing the redirect.