Linux Plesk how to add www to a subdomain

To create www prefix for subdomains you need to take the following steps:

1) Create vhost.conf file in the
/home/httpd/vhosts/domain.com/subdomains/subdomain/conf
directory with the following content:

ServerAlias www.subdomain.domain.com

2) Add appropriate A record to the DNS zone of the domain in
Server->Domains->domain.com->DNS

(specify this domain’s IP address instead of 192.168.1.1):

www.subdomain.domain.com.          A     192.168.1.1

3) Run wersrvmng utility to apply changes.

# /usr/local/psa/admin/sbin/websrvmng -v -a