subdomain folder under Website basedir

[qiubosu]

in ispconfig 3 control panel, go to Sites -> Subdomain for website -> Add new subdomain, then add a sub.example.com subdomain. should there be a folder sub.example.com under the Website basedir, e.g /var/www/sub.example.com? (for the domain, example.com, there is a folder under Website basedir, e.g. /var/www/example.com)

[till]

Just create a new website for the subdomain by clicking on new website, entering sub.domain.com in the domain field and click on save. By the way, thats described in the manual too.

[qiubosu]

thanks till,

after create a new website for the subdomain, does it need to create DNS records for this subdomain in control panel and in the registrar?

in the ispconfig 3 manual, when add a new website, for the Domain field, it says "Domain: This is the main domain of your web site, e.g. example.com (without subdomain like www).". does it mean without using sub etc. in front of example.com as subdomain?

the subdomain i want to create are development.example.com, test.example.com and production.example.com for different stages during the Drupal CMS SDLC. these subdomains don't point to the same Drupal codebase. can the ispconfig 3 control panel helps to achieve this?

by the way, why not use the "Subdomain for website" page to create subdomain? what is it used for?